Production of contact lenses. Leading contact lens companies

We work with various types hard contact lenses (Wohlk, Boston, Rose-K, SoClear, etc.).

Our specialists can choose exactly those contact lenses that will provide the highest quality of vision in your case.

What is rigid gas permeable contact lenses?

Sounds kind of intimidating.

Soft contact lenses are a much more pleasant name. However, you will be surprised that hard contact lenses allow oxygen to pass to the cornea in much more than conventional soft contact lenses and even the newest silicone hydrogel lenses, which are now the safest and most advanced soft contact lenses. And this indicator is almost the most important for those who constantly wear contact lenses.

Besides hard contact lenses provide better vision clarity, are more resistant to deposits, and are much cheaper than soft contact lenses, since one pair of lenses is designed to be worn for up to 1-2 years.

Why doesn't everyone wear hard contact lenses then?

First - You need adaptation, i.e. It takes some time to get used to wearing hard contact lenses. This time is very individual from 3-4 days to 2-3 weeks. And it doesn't hurt.

The second is to successfully wear hard lenses To you must be worn every day(with a few exceptions), because if you do not wear them for a while, then you will need some time to adapt again

Rigid contact lenses - an excellent option for those people who cannot achieve perfect vision in soft contact lenses. This is possible in several cases:

those people who make higher demands on the quality of vision, such as shooters, operating surgeons, pilots, jewelers, etc.;
those. who have astigmatism, especially a high degree, and due to this, 100% vision is not achieved in soft contact lenses;
patients with keratoconus (irregular shape of the cornea);
patients who need correction after previous corneal surgeries (laser surgeries to eliminate myopia, corneal transplantation, lens removal).
patients with problems when wearing soft contact lenses (corneal vascularization, recurrent eye inflammation, excess accumulation deposits)

If you are already using hard contact lenses and would like to purchase a new set, please note:

You can order or purchase hard lenses from us if the selection of lenses was made in our office. Rigid lenses cannot be ordered in absentia, eyeglass/soft lens prescriptions, or old hard lens options. To purchase lenses in our office, you need to make an appointment, take a break from wearing your lenses for a few days, and bring all the data you have with you (from examination data to old glasses and contact lenses).

Sign up for a consultation and hard selection contact lenses you can...
Ask a doctor about hard lenses online right now ... or by phone. 730-52-60, 730-53-35.

30-11-2011, 12:33

Description

In specialized laboratories of the country, both domestic and imported equipment is used for the manufacture of contact lenses.

The set of technological equipment includes: precision lathes for preliminary processing (facing, preliminary rounding) of workpieces; spherical lathes for processing the inner and outer surfaces of lenses (Fig. 73, 74); polishing machines for removing roughness and improving the cleanliness of the spherical surfaces of lenses (Fig. 75); special machines for polishing the edge of the lens and manufacturing tooling.

The machines are equipped with special devices and fixtures, which include: a centering device, sets of mandrels and satellites to hold contact lens blanks during their processing, a set of parts for the manufacture of polishers.

As a cutting tool for processing the concave, convex and edge surfaces of the lenses, diamond cutters of a special profile are used.

The composition of the technological equipment of the laboratory should also include: a heating cabinet for annealing blanks, an electric stove with a thermostat for sticking and centering blanks on mandrels, an ultrasonic bath for washing lenses and a magnetic stirrer for carrying out the process of hydration of soft contact lenses.

When processing the surfaces of contact lenses, the following technological materials are used:

Compositions for the manufacture of mass polishing;

polishing suspensions;

Adhesive materials used to secure and center lens blanks during their turning;

Polishing cloth.

In the late seventies and eighties, our country developed and then put into practice in the laboratories of contact vision correction the following materials:

1. Compounds for casting polishing pads, consisting of fine abrasive powder, paraffin and polyethylene or polypropylene wax.

2. Polishing slurry for polishing hard lenses when using polishing pads, consisting of specially prepared barium carbonate, glycerin and water.

3. Polishing suspension for processing soft lenses, consisting of finely dispersed magnesium oxide and kerosene.

4. Glued material (adhesive composition) for fixing and centering blanks of hard and soft lenses on a flat metal mandrel during lens turning, consisting of modified pine rosin and paraffin.

Manufacturing LCL by turning

Harvesting operations

For making rigid PMMA corneal contact lenses use cylindrical blanks with a diameter of 12.0 to 12.5 mm and a thickness of 4.0 to 5.0 mm.

Workpieces of the specified dimensions can be obtained from sheet material using a hollow tool (tubular drills or cutters).

Preparatory work

Before fabrication of LCL from PMMA blanks are annealed in order to relieve internal stresses in the material, leading to a change in the dimensions of the finished lens. To do this, the blanks are placed in a laboratory oven, in which the temperature is set to +130-135°C, where they are kept for at least 8 hours. Temperature fluctuations in the heating cabinet should not exceed ± 5°C. Then, over the next 8-10 hours, the temperature in the cabinet is gradually reduced to room temperature (temperature control is carried out using a thermometer). After cooling, the workpieces are removed from the heating cabinet and the residual stresses in them are checked on a polariscope for the presence of color patterns. Their observation is carried out from the side of the cylindrical generatrix, i.e., perpendicular to the axis of symmetry of the workpiece. In the presence of residual stresses, the annealing process is repeated. After annealing, the blanks go into production.

For polishing lens surfaces prepare lapping polishes. For their manufacture, a special, developed by the domestic industry, polishing material PMP-3 or PMP-1 is used. Polishing material PMP-3 is used for polishing concave surfaces, and PMP-1 - for polishing convex surfaces. The softening temperature of the polishing material is 100-120°C. It is possible to use imported materials.

To make a polishing pad, the material is melted in a porcelain cup to a creamy state. A brass shaping cylinder, put on a special substrate, is placed on a hot electric stove. Before casting inner walls cylinders are lubricated with vaseline oil. The mold is then filled with molten polishing material. After the mold has cooled, the polishing pad is removed from the cylinder. As a rule, several polishers are made at the same time.

Technological manufacturing process hard corneal lens turning method includes the following steps:

Calculation of technological parameters of processing (radii, thicknesses, diameters of the corresponding surfaces, spindle feed of a spherical lathe), based on the standard size of the manufactured lens;

Processing of the overall diameter and edge zone of the lens;

Turning and polishing the concave surface of the lens, its control;

Convex surface turning and polishing, its control;

Polishing of the edge zone of the lens;

Control of the geometric and optical characteristics of the lens.

Turning and polishing a concave surface

With the help of a special glued wax material HB-N, the blank from which the lens will be made is glued and centered on a steel substrate preheated on the tile. After cooling to room temperature, the substrate with the glued workpiece is fixed in the collet of the machine for turning the concave surface of the lens. In some machines, the substrate is not used, and the workpiece itself is fixed in the collet.

Processing begins with turning the workpiece to a given overall diameter of the lens. The diameter value is set using an appropriate dial indicator. Then the turning of the edge zone is performed, and then the concave surface of the lens is machined according to the specified parameters.

Formation of a multi-radius surface carried out in accordance with the calculated parameters specified in the "Tables of technological and control parameters of rigid corneal contact lenses" (1981), or according to photokeratometry. These parameters contain values of zone curvature radii, spindle feed rate, total lens diameter and optical zone diameter. Spindle feed refers to the amount of displacement of the workpiece along its axis in the direction of the axis of the rotary support.

The radius value is set by a dial indicator mounted on the machine's rotary support, and the feed rate is controlled by the spindle feed indicator. Turning starts from a surface with a larger radius. Its processing is carried out in several successive passes with a depth of cut of 0.2 mm for roughing and 0.05 mm for finishing. After that, the spindle feed indicator is set to zero. Then, according to the indicator of the rotary support, the next (smaller) turning radius is set in the table, the cutter is removed from the cutting zone, and the spindle moves to a given feed rate. Turning of the remaining surfaces is carried out sequentially. Then polishing is done.

First, prepare the polisher for work. To do this, the cast blank of the wax polishing pad is installed on a spherical lathe (for convex surfaces), where the working surface of the polishing pad of the required radius is machined.

Polishing is carried out on a special polishing machine (single or multi-spindle). The surface of the polishing pad is wetted with a polishing slurry. Polishing of the concave surface of the lens begins with the optical zone. The peripheral zone of the lens is polished on special polishing pads moistened with a suspension. Polishing time - from 0.5 to 1 min.

After polishing, the cleanliness of the lens surface is checked using a binocular microscope or magnifying glass with a magnification of 5-10x. The radius of curvature of the optical zone is measured on a radius meter. There should be no scratches, bubbles, gouges on the polished surface; the surface should be smooth, shiny, without rough areas. The radius of the optical zone must correspond to the specified one, within the established tolerance. If after the control it turns out that these requirements are not met, then the processing process is adjusted.

The controlled workpiece is removed from the steel substrate by heating on a tile until the sticker wax softens. After that, it is thoroughly cleaned of wax. Then the thickness gauge (indicator) measures its central thickness. The measured thickness value is taken into account when processing the outer (convex) surface of the lens.

Convex surface turning and polishing

The radius of curvature of a convex surface can be calculated using the following formula:

where: r1 - radius of curvature of the convex surface, mm;
r2 - radius of curvature of the optical zone of the concave surface, mm;
D - vertex refraction of the lens, in diopters; n is the refractive index of the lens material;
t is the thickness in the center of the lens along its axis, mm.
Depending on the given refraction, values of the central thickness from 0.1 to 0.5 mm are recommended.

On a preheated spherical mandrel with a radius corresponding to the radius of the optical zone of the semi-finished product, sticker wax is applied and the semi-finished product is glued from the side of the treated concave surface. Centering is carried out on a special centering device with an accuracy of 0.02-0.04 mm.

After cooling, the mandrel, together with the semi-finished product centered on it, is installed on the landing cone of a spherical lathe for processing a convex surface.

The calculated radius is set by the indicator located on the rotary support. With the help of another indicator mounted on the machine spindle, the thickness of the layer of material removed during processing is determined. The turning of a convex surface is carried out in several passes (similar to the processing of a concave surface) until the specified thickness is reached in the center of the lens.

Polishing of the convex surface is carried out with a special polishing pad moistened with a polishing suspension on a polishing machine (single or multi-spindle). Polishing time - from 2 to 5 minutes (depending on the material).

Cleanliness of the optical surface of the lens controlled with a binocular microscope or magnifying glass immediately after the manufacture of the lens before removing it from the mandrel with a central hole. Optical power is measured on a dioptrimeter. If during the control process it turns out that the processing results are not satisfactory, then the process is adjusted.

After finishing the polishing and checking the optics, the lens is removed from the mandrel and cleaned of adhesive wax.

In the manufacture of the outer surface of the lenses of negative refraction first, a spherical surface is machined with a calculated radius of curvature of the optical zone to a predetermined thickness in the center, and then a lenticular zone is machined with a predetermined edge thickness until mating with the optical zone. The radius of curvature of the lenticular zone is calculated and depends on design features lenses. When calculating, it should be borne in mind that the thickness of the lens along the edge should not exceed 0.2 mm, and the diameter of the optical zone of the outer surface should be at least 7.5 mm.

In the manufacture of the outer surface of lenses of positive refraction, first a spherical surface is machined with a calculated radius to a thickness in the center that exceeds the required one by 0.03 mm. The value of the radius depends on the thickness of the lens in the center and along the edge. Then the lenticular zone is machined, starting from the edge of the workpiece to the calculated diameter of the optical zone of the outer surface, which is selected 0.4-0.5 mm larger than the diameter of the inner surface. The indicator sets the calculated radius of the optical zone. By turning the cutter mounting support and correspondingly feeding the workpiece, the cutter tip is aligned with the peripheral portion of the optical zone, and the optical zone of the convex surface is processed. Polishing is carried out on a polishing machine using a special polishing pad moistened with a suspension.

The production of FPJCL is carried out according to the same scheme, but less intensive processing modes are used and special formulations for cleaning and polishing these materials.

Fabrication of spherotoric rigid corneal contact lenses

When processing spherotic lenses, the concave spherical surface of the lens is first machined according to the method discussed above, and then, to obtain a toric surface on the periphery, it is processed with a toric tool (usually a grinder and polisher) with specified radii of curvature of the surfaces in two mutually perpendicular planes (Fig. 76) . The number of prepared toric tools depends on the required number of toric surfaces in the flattening (sliding) zone.

For turning a grinder use a special lathe designed for the manufacture of toric tools. In this case, the following rules should be followed:

1. According to the difference between the radii in the main meridians, the transverse displacement of the spindle relative to the rotary caliper is set. The movement is controlled by a dial indicator. For example, for a toric tool with radii of 8.0/8.5 mm, this value, called the toric difference, will be 0.5 mm.

2. By rotating the rotary caliper, the tool blank is machined to a depth of not more than 0.05 mm for each pass, until a given radius is obtained, counted from the indicator of the rotary caliper.

Then the manufactured tool is installed in special device("toric fork") polishing machine.

The substrate with the machined workpiece is rigidly fixed to the leash of the toric fork. Then the leash is installed in the grooves of the fork so that the concave surface of the workpiece rests on the working surface of the toric tool. The pin of the upper spindle of the polishing machine fixes the leash of the toric fork. By vertical movement of the rocking head of the finishing machine, it is necessary to achieve such a position of the workpiece that it moves only in the central part of the toric tool. Grinding is carried out with grinding powder M7 and M3 until a given size of the optical zone is obtained. The grinding time depends on the ratio of the lens radii and the toric difference of the tool. The control of the resulting size of the optical zone is carried out using a measuring magnifier with a magnification of 10x.

Polishing of the toric peripheral zone is carried out on a soft polishing pad with a special polishing paste. The polishing of the optical zone is carried out in the same way as for axisymmetric lenses.

They are not in the most favorable conditions, besides, they are deprived of state support, but companies are doing everything in their power to win the fight for their place in the market. In this article, we will review the state of affairs in this segment of the domestic manufacturing sector.

If you look at the developed markets for contact vision correction, say the EU countries, then, as follows from the regularly published reports of various agencies (for example, "Eurom Contact"), it is clear that these markets are mainly filled with planned replacement contact lenses manufactured by large companies . These products have replaced traditional wear contact lenses from the market to a certain extent. According to leading managers of large manufacturing companies, traditional contact lenses occupy a new niche for them: more and more often these are contact lenses for those people who have limited funds, as well as special contact lenses made according to an individual prescription. Although, according to some manufacturers, the latter are, one might say, the bread of contact vision correction laboratories operating in various regions of the country.

Apparently, a similar fate awaits traditional soft contact lenses in our country, although they currently occupy a fairly large market share (according to various estimates, up to 45% of the market). Do not just think that this conclusion was made hastily - in principle, the Russian production workers themselves agree with it, with whom we managed to talk on this topic, and it is to them that we will give the floor in the published material. But first, let's list those companies that are engaged in the production of contact lenses. This enterprise "" (Vologda) is the largest in terms of production, the firms "Opticon" (Moscow), "" (Ufa), "Octopus" (Samara), "Nevskaya optics" (St. Petersburg), "Contlins", ( Arkhangelsk), "Likont" (Volgograd), PE Kunina (Belgorod) and some others. All of them produce traditional wear soft contact lenses by turning.

To find out what problems our production workers face and how they see the prospects for the development of their enterprises, we talked with representatives of a number of the above-mentioned firms and asked them to answer a number of questions. Viktor PROSYANYUK, director of Concor, Boris DYMAN, director of Opticon, Ural YANTURIN, a representative of Optimedservice, and Sergey GOLOSHCHAPOV, one of the leaders of the production and development company Octopus, shared their thoughts with us.

Veko: What share of the contact lens market, according to your estimates, is occupied by domestic products?

Viktor Prosyanuk: According to our research, about 50 percent, half of which are contact lenses manufactured by Concor.

Boris Dyman: At present, it is difficult to estimate the market share occupied by domestic traditional contact lenses, but based on the total production volumes - which is approximately 30-40 thousand pieces per month - it can be assumed that this share is 10-15 percent, not more.

Veko: How do you see the prospects for the development of domestic production of contact lenses?

Viktor Prosyanuk: The sad thing is that things are not going very well for Russian production workers at the present time, some enterprises are even closing down. It turns out that there is no single development program, no support government programs, and our production facilities are forced to follow the lead of large Western companies. One of the main problems is dictated by our market price policy. If, say, in the West, traditional contact lenses are sold for $8-10 a piece, then we are forced to set a price for planned replacement contact lenses - $2-3, as a result of which we work at extremely low profitability, almost at the limit. As a result, we cannot afford a large advertising campaign and the purchase of more modern production equipment necessary for the manufacture of modern products - planned replacement contact lenses, contact lenses in blister packs, contact lens care solutions.

Boris Dyman: The future belongs to planned replacement contact lenses, which are practically impossible for our entrepreneurs to organize. Therefore, traditional contact lenses will be forced to take a niche product for citizens with a low level of material income, as well as for those people who are conservative in their views and are accustomed to these contact lenses, although the funds allow them to buy more expensive planned replacement contact lenses. And it will definitely happen - a year earlier or a year later.

Sergey Goloshchapov: I do not see any positive trends in the field of domestic production of contact lenses. I just look at things realistically, since I myself am a co-owner of a network of optical salons and I see the dynamics of growth in sales of planned replacement contact lenses from 10-15 percent in 1997 to 87 percent in 2003. Sooner or later, traditional contact lenses will be forced out of the market, and our manufacturers, like in the West, will have to switch to the production of special contact lenses - for keratoconus, toric (astigmatic contact lenses), with high refraction; the rest will be occupied by scheduled replacement contact lenses. And it is not possible to start the production of planned contact lenses in Russia from scratch, unless Western companies themselves build production facilities here and finally bring down prices.

Veko: How would you assess the state of the contact vision correction market, does it contribute to the development of our enterprises?

Viktor Prosyanuk: The market has great potential - while the proportion of the population using contact lenses is 1.5 percent. If you look at the countries of Europe, then this share is 5-7 percent. It is to be expected that our market should reach a similar proportion of contact lenses. Therefore, the market has great potential. In the contact correction market itself, alarming trends are observed - the number of primary patients is decreasing. This suggests that contact doctors should think more about their civic responsibility: their task is not to sell contact lenses, but to provide a person with full vision so that he is satisfied with the service. Then he will continue to use contact lenses. In the meantime, it turns out that in society there is a growing number of misconceptions about contact lenses as a method of correction, which is fraught with terrible complications.

Sergey Goloshchapov: In 2003, our sales grew by 20 percent, and in principle, since the company was founded, the annual growth has been 15-20 percent. Sales are currently underway in all regions Russian Federation and other CIS countries. The most popular contact lenses are "Elite-38" with 38 percent moisture content.

Internal competition between domestic producers was established on the market, so that the price froze in the region of 2-2.5 dollars per unit of production. Profitability is declining and currently it is very low - although the prices of the cost of materials do not change, the costs of rent, electricity, wages and so on, and consequently, the cost also increases.

Ural Yanturin: Behind last year sales of contact lenses grew by 20 percent. This is due to the fact that we pursued an active marketing policy: we participated in all regional and central exhibitions, gave a lot of advertising. Are there any difficulties? Yes, in principle, no - there is a good demand for our product. You just need to work harder - and things will go well. The profitability of production, of course, is low. But you can stay afloat, you just need to work.

Eyelid: Many experts believe that lenses with 38 percent moisture content are unsafe for the health of patients' eyes. Is it worth it then to produce such lenses at all?

Viktor Prosyanuk: Of course, we understand that contact lenses with 38% moisture content cannot be recommended to be worn all day long. That is why we urge doctors to remember their civic responsibility and sell not contact lenses, but vision. It is necessary to explain to patients the peculiarities of wearing contact lenses with low moisture content. Again, recognizing the disadvantages of 38% moisture contact lenses, we are releasing 70% moisture contact lenses. And now 55% contact lenses should be officially registered. We are also going to produce contact lenses with a 67% moisture content from the materials of the Kontamak company - Contaflex 67.
Personally, I myself have nothing against planned replacement contact lenses: they need to be in stock. But based on the situation in our country, offices need to have traditional contact lenses. Not all residents of the country can now afford to change contact lenses every month, it is expensive for them. They need traditional contact lenses that last longer before being replaced with new ones.

Veko: Are there any difficulties with lens materials?

Viktor Prosyanuk: Of course I have. For example, “seventies” (with a 70% moisture content) from “Lyamda Polytech” does not really suit us - its material characteristics fluctuate from batch to batch, so each time you need to reconfigure the calculation tables before production, having previously run several dozen blanks. Also, when contact lenses are hydrated, the vinyl-propylene bonds of the polymer are poorly washed out, as a result of which some patients complain of a burning sensation in the eyes.

Veko: How can your enterprise counter the expansion of large Western manufacturing companies?

Viktor Prosyanuk: We can oppose large companies with our strengths. Firstly, our contact lenses have a wide range of parameters - from -20 to +20 diopters. As a result, contact vision correction rooms often buy lenses with a refraction of up to -6 diopters from, say, Bausch and Lomb, and the rest from us. And then, having tasted them, they buy all the refractions from us. Secondly, with turning and three-stage quality control, we give marriage only at the level of 1.5 percent. The contact lens is checked for chips, microcracks, and so on after being dry-turned, then after hydration, and again before packaging. And another thing - contact lenses produced by stamping on large industries, such as, say, the same company Bausch & Lomb - they, as far as I know, only check the quality of 10 percent of a batch of goods.

Therefore, and I am convinced of this, according to our GOSTs, exported contact lenses of planned replacement should be considered a marriage in 90 percent of cases. Our traditional contact lenses are much better quality. Please understand me correctly: I am not against any specific Western companies, but against the ideology of the dominance of planned replacement contact lenses. These contact lenses are produced with lower quality requirements, and accordingly, they have a sharply reduced recommended wearing period. Traditional contact lenses can be worn more, as their quality is higher.
Thirdly, we have the widest dealer network - there are no regions where we would not have an official representation. Therefore, our contact lenses are more affordable, and therefore the demand for them exceeds the supply.

Sergey Goloshchapov: As for being able to compete with Bausch & Lomb, it's pointless. Our contact lenses are designed for low-income people who cannot afford to spend more. If they have other money, they will definitely switch to planned replacement contact lenses - health is more expensive. Again, our production base is becoming obsolete. Ten years ago we bought new Gfeller machines. Now they are already morally obsolete, and physically wear out. Maybe five more years. And then what? Then there will be contact lenses from Bausch & Lomb, Johnson & Johnson and other major Western manufacturers everywhere.

Ural Yanturin: Our contact lenses hold their shape well and are easy to handle when putting them on and taking them off, which appeals to some patients. But the future, of course, belongs to planned replacement contact lenses, so we understand that sooner or later the production of traditional contact lenses will be forced to switch to the production of special contact lenses, as happened in the West.

Veko: How to survive with such bleak prospects?
Sergey Goloshchapov: That's why you have to deal not only with contact lenses, but also with other areas of the optical business - for example, glasses, laser correction.

. . .
So, as follows from the statements of most of our interlocutors, the prospects for the domestic production of traditional contact lenses are not very bright. The market is becoming more and more filled with low-cost elective replacement contact lenses produced by large Western companies, there is a growing awareness of the population that elective replacement contact lenses are safer for eye health than conventional contact lenses with low moisture content. Accordingly, sales of foreign-made contact lenses are growing. However, sales of Russian companies are also growing at the same time. Thus, most of our interlocutors noted an increase in sales of contact lenses of their own production over the past year - an average of 10-15%. In principle, this is explained by the fact that so far the market for contact vision correction is growing in the country and its filling is due to the products of both Western companies and Russian ones. This allows our manufacturers to stay afloat, and in the case of Concor, for example, even expand production and release new brands of contact lenses, as demand exceeds supply.

As for the future, as follows from the words of our interlocutors, it is still rather vague. As can be seen from the answers to the questions, the forecasts are disappointing: either a reduction in production, or a complete re-profiling or even leaving the market for contact vision correction. Only Concor is the most optimistic in this regard, as the largest production.

Russian manufacturers of contact lenses

Octopus

Production and innovation company "Octopus" is one of the largest enterprises in the Volga region that produces high-quality soft and hard contact lenses. Contact lenses are made from the material of the company "Contamac" (Great Britain) by turning on the machines of the company "Gfeller" (Switzerland) using computer facilities management. Here, the quality control of each manufactured contact lens is carried out.
The company was formed in 1993; thus, this year she turns 11 years old. In 1994, the company acquired the production equipment of Gfeller (Switzerland), and a little later, with the help of specialists from Lamda Polytech Ltd. production has been upgraded. The range of manufactured contact lenses has also expanded: now Octopus produces soft contact lenses with 38- and 55% moisture content Elite 38 and Elite 55 from imported materials from Contamac, as well as hard and hard gas-permeable contact lenses. In addition to colorless contact lenses, Octopus manufactures cosmetic contact lenses using Lamda Polytech Limited equipment.

Optimedservice

The Scientific Medical Association (NMA) "Optimedservice" was established in 1993 and today occupies a leading position in the ophthalmological market of the Ural region. Since 1994, the company has been producing soft contact lenses under the brand name "" on a computerized production line from City Crown (Great Britain). One type of lens is produced: "Optimed-38" with 38% moisture content.
See more here...

The firm "Concor" appeared in 1991. Initially, the production of contact lenses was carried out on domestic equipment. However, it did not provide the quality of contact lenses sufficient to create competitive products, and in 1993 it was decided to purchase from Lamda Polytech Ltd. refurbished Chase machines. This was a qualitative step forward, and products from Concor began to gain popularity among contactologists.
Today the company produces soft contact lenses under the brand name "Concor" - from the materials "Hypolan-2", "Benz-38 tint", "LM-70VP". Traditional soft contact lenses with 55% moisture content are in the process of registration.
According to the research conducted by the company, at present, the products of the Concor company occupy Russian market 25%, another 25% is the share of the presence of other domestic manufacturers, and 50% are Western-made products, half of which are Bausch & Lomb.

opticon

The company "Opticon" was founded in 1991 by employees of NPO "Medoborudovaniye", who had great experience in the production of the first domestic soft contact lenses from the Hypolan material (as well as in the development and creation of this material itself). In addition to Gipolan, the company tried to make contact lenses from materials from Lamda Polytech Ltd. and Vista, but ended up choosing Benz and LM materials.
Opticon manufactures soft contact lenses under trademarks"Opticon 38" and "Opticon 72". The former are made from Benz 38 material, the latter from LM-70; Colored versions of these lenses are also offered.

Vadim Davydov, Veko No. 5 (79), 2004

Contact lenses were invented over a hundred years ago. For a long time, only hard lenses were produced, but in 1960 soft contact lenses were invented and became widespread. Unlike hard lenses, they are comfortable to wear and do not take long to get used to. Today, about 90% of users prefer soft lenses made from elastic, gas-permeable materials. Properly selected, they provide the wearer with comfort, safety and perfect vision correction. Modern rigid lenses are also gas-permeable, but because of the difficulty in getting used to them, they are usually used only in certain, particularly difficult cases.

Lens manufacturing methods

The production of modern contact lenses is based on several technologies:
- turning (turning);
- casting;
- centrifugal molding;
- combined methods, combining elements of the above methods, for example, the reverse reverse process.

Turning

The turning method is used for the manufacture of both soft and hard. Their production is carried out on the same equipment, but has some differences. Disc-shaped blanks are processed on special lathes, this process is almost completely automated. The computer program monitors compliance with all parameters.

At the first stage, a diamond-tipped cutter forms the internal curve of the lens, then the surface is polished to give it absolute smoothness. Next, the outer surface is processed, which will be in contact with the eyelid, and the desired diameter is given to the workpiece. Outside surface and the edges of the lens are also carefully polished. At the end of this stage, its thickness and other parameters are measured using a very accurate instrument.

The difference between the production of soft lenses lies in the fact that after the turning stage they are subjected to hydration - they are immersed in a saline solution with an optimal pH factor. Hydrogel and silicone hydrogel, which are used to make soft lenses, absorb moisture well and swell, increasing to the desired size. In the course of hydration, the hard workpiece acquires the missing softness and elasticity. At the end, the finished product is checked for compliance with optical and geometric parameters. Lenses are cleaned, packaged and labeled before being sold.

Casting

Casting begins with the manufacture of a matrix with specified parameters that correspond to the characteristics of the future lens. From the matrix, plastic form copies are made, which can be both disposable and reusable. The lower half is filled with liquid polymer and covered top, forming an internal space having the shape of a lens. The workpiece is irradiated with ultraviolet light, under the influence of which the polymer hardens. The lens is then hydrated, measured, cleaned and packaged.

Centrifugal molding

The technology of centrifugal molding was developed by the Czech inventor of soft lenses, Otto Wichterle. A special mold with a concave bottom and cylindrical walls is filled necessary quantity monomer. In the process of its rotation on special equipment, the composition spreads over the inner surface and hardens. The shape and thickness of the resulting lens depend on the amount of polymerization mixture and the speed of mold rotation.

Reverse reverse process

The reverse reverse process successfully combines the two technologies described above. First, the convex side of the lens is obtained by centrifugal molding, then it is processed by turning inner part. The resulting lens acquires the advantages of each of the methods - smoothness outer surface and edges are combined with excellent functional qualities obtained during turning.

Contact lenses are small clear lenses that are placed directly on the iris of the eye. The main purpose of such lenses is the correction of refractive errors (improving its sharpness). The exception is decorative and cosmetic contact lenses, which are mainly used as decoration, although they often perform a dual function - vision correction and eye decoration.

According to statistics, at least 125 million people use contact lenses, which is approximately 2% of the entire population. More than 40% of contact lens users are young people aged 12-25.

People wear contact lenses for optical or functional reasons. Lenses, compared to glasses, are usually able to provide better peripheral vision and do not "fog" in extreme weather (rain, snow, humidity). This makes them more suitable for outdoor use, especially during active sports. There are also a number of ophthalmic diseases (for example, aniseicoria, etc.), the correction of which is more effective when wearing contact lenses, rather than glasses.

The main optical difference between contact lenses and glasses is the lack of distance between the eye and the optical glass, which provides distortion - the visibility of objects without distortion.

A bit of history

Incredibly, the first idea to apply contact correction came to Leonardo da Vinci back in 1508. While sorting through the archive of his works, scientists came across drawings of a ball filled with water, through which a visually impaired person could look at surrounding objects. In addition, in his notes, schemes of lenses were found, which can be safely called the prototype of modern ones.

In 1637, the work of Rene Descartes was published, with drawings of an optical instrument. The device was a glass tube filled with water, to the end of which a magnifying glass was attached, while the other end was attached to the eye. This device was subsequently modified by the English physicist Thomas Young, who used a shorter tube, thereby compensating for the shortcomings of refraction.

The German physiologist Adolf Fick in 1888 described a glass lens with optical power. And made optical lens and implemented its application in medical practice ophthalmologist August Müller in 1889. His lens became a new method of correction and the subject of his doctoral dissertation.

Until the second half of the last century, organic glass (PMMA) served as the material for the manufacture of contact lenses. Such lenses were stiff and uncomfortable to wear, causing a sensation of a foreign body in the eye. In addition, they absolutely did not allow oxygen to pass to the cornea, which is necessary for its normal functioning. In 1960, the Czech scientist Otto Wichterle synthesized a new type of polymer (HEMA) from which soft contact lenses were first made. HEMA polymer had the ability to absorb water (up to 38%), after which it became elastic and soft. As recently as 10 years ago, a new generation of contact lenses was created - silicone hydrogel. These soft lenses provide even more comfort and absolute safety when worn.

Today, I use a lot of classifications for contact lenses: by the material of manufacture, by the frequency of replacement (the period after which the lenses are replaced with new ones), by the mode of their wearing (daily, prolonged, continuous, etc.), by design (spherical, toric, multifocal ), according to the degree of transparency / color (transparent, colored, decorative). But all of them are divided into two main groups: soft lenses and hard ones.

Soft contact lenses are preferred by up to 90% of all contact lens wearers. In turn, such contact lenses are divided into hydrogel and silicone hydrogel.

Rigid contact lenses are usually used to correct difficult cases pathologies of vision (for example, with high astigmatism and keratoconus), in addition, only they are used in orthokeratology, a relatively new direction in ophthalmology. The new generation of rigid lenses not only keep their shape perfectly, which makes them more comfortable to use, but also provide a high degree of oxygen transmission to the cornea. Such lenses are called rigid gas permeable contact lenses.

Colored contact lenses are designed to radically change the color of the iris, and tinted, to enhance or change the shade of the existing color. Such lenses can be made with diopters, in which case, in addition to changing the color of the eyes, they will improve vision. But in most cases, such lenses are produced "zero" - without diopters and are necessary only for a cosmetic effect.

On the color perception of visible objects, colored and tint lenses do not affect, since they are transparent in the center. True, such lenses are not recommended for use in low light (at dusk and darkness), because the human pupil expands with a lack of light and then the colored part of the lens will fall into the visibility zone, which will cause visual difficulties. Such lenses should not be worn while driving or engaging in activities that require high attention.

Designation of parameters of contact lenses

All contact lenses have the following characteristics (parameters), which must be indicated on the sales packaging:

Manufacturing material.
Lens diameter (D, BCR).
Radius of curvature (BC, BCR).
The optical power of the lens.
The thickness of the center of the lens.
Axes of the cylinder.
Construction (design).
Optimal wearing mode.
replacement frequency.

Lenses with a long wearing period (6-12 months) are usually packaged in special bottles. For more frequent replacement lenses, blisters are used as packaging.

Wearing mode - the period of time that the lenses can safely remain on the eyes:

Day (put on in the morning, removed before bedtime).
Prolonged (worn for 7 days, not removed at night).
Flexible (worn 1-2 days, not removed at night).
Continuous (worn up to 30 days continuously, not removed at night). A similar regimen is possible for some types of silicone hydrogel lenses and requires the consultation of an ophthalmologist.

Night (should be put on before going to bed, and removed in the morning). Orthokeratological lenses after which the patient sees perfectly all day without additional means of correction.

Design (construction) of contact lenses

Spherical. Their purpose is the correction of myopia and hypermetropia.
Toric - for the correction of myopia and hypermetropia with concomitant astigmatism.
Multifocal - for the correction of presbyopia.

Improving the quality of vision in any type of lens is achieved by their aspherical design. Various polymers are used in the manufacture of contact lenses. The main part is made up of hydrogel and silicone-hydrogel materials, of which there are about 10 types.

The properties of a contact lens are mainly determined by the material of its manufacture. The main characteristics of the material for contact lenses are considered to be: the content of water in it and the permeability of oxygen.

Low water content (<50%).
Average water content (50%).
High water content (>50%).

The more water the hydrogel lens contains, the more oxygen the cornea will receive, which has a positive effect on eye health. But the increase percentage water in the lens, makes it softer, making it harder to handle. Therefore, the water content in hydrogel lenses usually does not exceed 70%.

The main indicator for silicone hydrogel lenses is the oxygen transmission coefficient (Dk / t), which has nothing to do with water content. Wherein:

Dk is the oxygen permeability for the lens material.
t is the thickness at the center of the lens.

The Dk / t for hydrogel lenses is usually in the range of 20-30 units. For daytime wear, this is sufficient, but much higher values are needed to keep the lenses on the eyes at night. Silicone hydrogel lenses have a Dk/t of approximately 70-170 units.

The diameter of a contact lens and its radius of curvature affect how the lens sits in the eye. As a rule, lenses are produced with one or two values of the radii of curvature. If a contact lens does not fit properly due to a discrepancy between the radius of its curvature and the shape of the cornea, serious discomfort occurs that can lead to refusal to wear lenses.

The main optical indicators of a contact lens are: the power of the sphere (with a plus or minus sign, in diopters), the power of the cylinder (indicated in diopters), the localization of the axis of the cylinder (indicated in degrees). The last two parameters are only needed for toric lenses that correct astigmatism.

The parameters of indicators of contact lenses for one and the other eye of the patient may be different.

Terms of Use

Incorrect selection of contact lenses and their improper fit, interference and discomfort are inevitable. To eliminate it, you should contact an ophthalmologist. With a larger radius of curvature of the lens than necessary, they seem to “float” in the eye, and with a smaller one, on the contrary, they “get stuck” and this part of the cornea ceases to be supplied with oxygen. In both cases, such lenses should be replaced with lenses with the desired radius of curvature. Properly fitting lenses tend to move slightly when blinking (landing without rigid fixation) but, most of the time, they are in a central place. At prolonged wear lenses with a smaller radius of curvature, corneal hypoxia often occurs without oxygen, which increases the risk of infectious processes, since with sufficient oxygen, infectious agents do not survive.

You can swim with lenses only if you use special sealed goggles or a swimming mask. In lenses, you can not go to the sauna and bath. If unboiled water gets on them (shower, pool), it is necessary to replace them with a fresh pair. Contact lenses are designed to be worn in all ambient temperatures, including extreme heat and cold.

Wearers of contact lenses are required to undergo annual examinations by an ophthalmologist.

Possible Complications

The use of contact lenses can lead to some complications, including:

Infectious diseases (, dry keratoconjunctivitis, etc.).
allergic reactions.
Reactions of hypoxia with oxygen deficiency for the cornea.
Mechanical damage cornea.

Neglecting the rules of hygiene or lens care (it is necessary to treat them with a special cleaning solution), infection of the mucous membrane may occur. Violation of the terms of wearing lenses of a planned replacement or wearing lenses with a low oxygen permeability, it is possible for blood vessels to grow into the cornea of the eye (neovascularization) and other complications, which are often irreversible. They become a contraindication to the further use of contact lenses.

Manufacturing of contact lenses

Manufacturing of contact lenses is carried out in several ways: centrifugal molding, casting, turning. There are also methods that combine all of the above methods.

Turning. With it, "dry" polymerized blanks are processed on a lathe. Lenses of complex geometry are obtained through the use of computer control programs. After turning, the lenses are polished and saturated with water (hydrated) to the required parameters, then they undergo chemical cleaning. final stage manufacturing in this case, is the tinting of the lens, sterilization, testing, packaging and labeling.
Casting. This is less labor intensive than the turning method. First, a special metal mold-matrix is made for the lens. Then, plastic molds-copies are cast on the matrix and a liquid polymer is poured into them, which hardens under the influence of ultraviolet radiation. Finished lenses are polished, hydrated, tinted, sterilized and packaged.
Rotation molding is the oldest method of manufacturing contact lenses. With it, a liquid polymer is injected into a mold rotating at a certain speed and exposed to it. high temperature and / or UV radiation, which is necessary for its hardening. Then the workpiece is taken out of the mold, saturated with water and subjected to processing identical to the turning method.

One example of a combined contact lens manufacturing process is the reverse process. With it, to obtain the front surface of the lens, the method of centrifugal molding is used, and to obtain the back, turning is carried out.

The world's largest manufacturers of contact lenses are recognized: Johnson & Johnson (product "Acuvue"), Neo Vision, Bausch & Lomb, etc.

You can find more information about individual types of contact lenses in the relevant sections:

For the manufacture of contact lenses of the latest generation, highly sensitive soft materials are used, which are particularly smooth. In order to facilitate the manipulation of such lenses, to maintain the integrity and sterility of the contact surface, special tweezers are produced. They are used to remove lenses from the container, tweezers help when removing contact lenses and immersing them in the solution poured into the container bath, as well as in the process of rinsing them with special disinfectants.

Everyone who uses contact lenses knows the need to keep them perfectly clean, because the health of their own eyes and the quality of vision depend on it. In this regard, in order to avoid infection with eye infections, along with the purchase of a new pair of lenses, it is worth buying a container for their storage, as well as a special solution that the best way suitable for both the eyes themselves and for optics.

Baush + Lomb's new contact lenses, dubbed SofLens Daily Disposable, are affordable option daily lenses. They do not require everyday care and provide clear vision at any time and in any light thanks to improved optics.

Colored contact lenses Adria Color of the Korean company Interojo are in great demand and are very popular. These are lenses that allow you to correct various degrees of myopia and, as well as change the tone, color and even the appearance of the eyes completely. In the production of colored lenses, an innovative coloring technology is used. Thanks to her, the dye is as if locked inside the lens material, which increases the resistance to fading and makes wearing products of this brand absolutely safe.

Daily contact lenses are a prime example of convenience, comfort and safety. Their other name is “daily replacement lenses”, because they are designed to make the look rested and bright every new day. What distinguishes them from the already familiar lenses of planned replacement is that every morning it is necessary to open a new package, and every evening to dispose of lenses that have become unusable throughout the day. Actually, this is what makes silicone hydrogel daily lenses so reliable and comfortable.