Visual acuity. Determination of visual acuity Which vision is better: 0.5 or 0.8

In the section on the question Which vision is better -0.8 or -0.6. I know that 100% is 1. But I’m sitting and dumb.... A person sees better if he has 0.8 or 0.6? given by the author tales the best answer is that Sivtsov’s tables have been used for 100 years... If at a distance of 6 meters from them you see the 10th line from above, it means your vision is 100% or 1... The lines above are 9th, 8th and so on, respectively O. 9.. 0.8 and so on.. . The closer to one, the better and vice versa... "Far-sighted" go for 1 - 1.2...1.3... Approximately, but enough for work... So if you have O. 8, you are in the first group, since vision 0.8 is BETTER than 0.6...

Reply from Sedge[guru]
-0.6 is better than -0.8

Reply from Andryukha[newbie]
if 0.8

Reply from Neurologist[guru]
The closer to 1, the better it sees.

Reply from Master"ICE[guru]
no, not better, there is such a concept as myopia and farsightedness.

Reply from Marianna Afanasyeva[guru]
Naturally 0.8, closer to one. but this is if it is calculated by lines in the table. if converted to Daltons, then worse -0.8D.

Reply from Alexandra Burimskaya[guru]
join in reality... if the value is negative, then the larger one, the cat has a smaller value -0.8 -0.7 -0.6....0....+0.6 +0.7 and. etc good luck)))

Reply from Vasily Timofeev[expert]
Which is closer to zero - -0.6 This is better than -0.8

Reply from Karen Avakian[newbie]
Well, smear... 1 (one) is 100%, and 0 (zero) corresponds to 0%. But what is there between one and zero? decimal parts. The smaller they are, the worse the vision is considered. so 0.8 is steeper than 0.6. 1 - 100% 0.9 - 90% 0.8 - 80% 0.7- - 70% 0.6 - 60

Reply from Bulgarian[master]
- means myopia, and the numbers are % vision deterioration, so -0.8 is already, -10 is practically blind

Reply from Gocha Zaikin[newbie]
Bulgarian wrote crap

Visual acuity is expressed in 2 ways:

1 way.

In the CIS countries - fractions of one: 1.0 - normal vision, 0.9; 0.8, etc. up to 0.1 - determined by the number of lines starting from the top that a person sees according to the Sivtsev or Golovin table from a distance of 5 meters. Studies are carried out for each eye separately: first, the visual acuity of the right eye is determined, then the left eye.

When examining visual acuity from a different distance (less than 0.1 - if a person from 5 meters does not recognize the signs of the top row), the person being tested is brought closer to the table and asked every 0.5 meters until he correctly names the signs of the top row. The value is calculated using the formula:

V=d/D, Where

V - visual acuity;

d is the distance from which the study is carried out;

D is the distance at which a normal eye sees a given row.

But it is better to use Polyak optotypes to determine visual acuity less than 0.1 s 5 meters.

To determine visual acuity in children, the Orlova table is used.

The distance of 5 meters was chosen for a specific reason: with emmetropia, the point of clear vision is as if at infinity. For the human eye, infinity begins at a distance of 5 meters: when an object is located no closer than 5 meters, parallel rays are collected on the retina of an eye with emmetropia.

In English-speaking countries, visual acuity is usually determined using the Snellen chart and is usually expressed as a simple fraction: the numerator is the distance from which the test is performed (usually 20 feet ~ 6 meters), and the denominator is the distance from which the emmetropic eye sees the sign. correctly read by the subject (20/20 - equivalent to 1.0; 20/200 ~ 0.1).

Method 2.

Wikimedia Foundation. 2010.

See what “Definition of visual acuity” is in other dictionaries:

VISUAL ACUITY- represents the ability of the eye to separately perceive two points, between which there is a certain distance. O. z. one of the most important functions of the organ of vision, and the state of its hl. arr. Our ability to navigate our environment depends...

FIELD OF VIEW- represents a space, all points of which are simultaneously visible with a fixed gaze. With monocular fixation, the image of the object being fixed is obtained in the area of the macula, while images of objects located on the macula... ... Great Medical Encyclopedia

Conducting pathways of the visual analyzer 1 Left half of the visual field, 2 Right half of the visual field, 3 Eye, 4 Retina, 5 Optic nerves, 6 Oculomotor nerve, 7 Chiasm, 8 Optic tract, 9 Lateral geniculate body, 10... ... Wikipedia

VISUAL ACUITY- Ability to see small details of objects in the field of view. Visual acuity is usually expressed in degrees of the visual angle formed by the object in question, which can only be seen, or in the size of the object itself. In clinical... ... Explanatory dictionary of psychology

REFRACTION ANOMALIES- honey Refraction of the eye is a characteristic of the refractive power of the optical system of the eye, which is in a state of rest of accommodation, determined by the position of the rear main focus relative to the retina, expressed in conventional units of diopters (Dopters) ... Directory of diseases Wikipedia

Hello, dear readers of the blog site. Not so long ago, we discussed in some detail the topic of using emoticons on the VKontakte social network. The main codes of Emoji emoticons were also given there (about a thousand - for all occasions). If you have not yet read that publication, I strongly recommend that you do so:

What do text emoticons made up of symbols mean?

Let’s continue to study the meanings of the most common options writing certain emoticons using ordinary (non-fancy) symbols. Are you ready? Well, then let's go.

Initially they became widespread, i.e. lying on their side (see the above examples of laughing and sad faces). Let's see what other combinations you might come across on the Internet and what they mean (how to decipher them).

Indication of emotions by emoticon symbols

Joy or smile 🙂 is most often depicted using the symbols: :) or :-) or =)
Uncontrollable laughter 😀 (equivalent to the expression: :-D or :D or)))) (under-smile used mainly in RuNet)
Another designation for laughter, but more like mockery 😆 (equivalent): XD or xD or >:-D (schadenfreude)
Laughter to tears, i.e. what does the “tears of joy” emoticon mean 😂: :"-) or:"-D
Insidious grin 😏: ):-> or ]:->
A sad or sorrowful emoticon 🙁 has text meanings: :-(or =(or:(
Symbolic designation of a very sad smiley 😩: :-C or:C or (((((again, a variant of the under-smiley)
Mild displeasure, confusion or puzzlement 😕: :-/ or:-\
Strong anger 😡: D-:
Text designation of the neutral attitude emoticon 😐: :-| either: -I or._. or -_-
The symbolic meaning of the admiration emoticon 😃: *O* or *_* or **
Decoding the emotion of surprise 😵: :-() either:- or: -0 or: O or O: either o_O or oO or o.O
Options for what an emoticon of great surprise or bewilderment can mean 😯: 8-O
either =-O or:-
Disappointment 😞: :-e
Fury 😠: :-E or:E or:-t
Confusion 😖: :-[ or %0
Sullenness: :-*
Sadness: :-<

Meaning of text emoticons emotional actions or gestures

What does a winking smiley mean in text-symbolic form 😉: ;-) or;)
Sad joke: ;-(
Happy joke: ;-)
Options for designating a crying emoticon 😥 or 😭: :_(or:~(or:"(or:*(
Joyful crying (means “tears of joy” emoticon 😂): :~-
Sad cry 😭: :~-(
Angry cry: :-@
Kiss in text notation 😚 or 😙 or 😗: :-* or:-()
Hugs: ()
To show your tongue (means to tease) 😛 or 😜: :-P or:-p or:-Ъ
Mouth shut (means shh) 😶: :-X
It makes me sick to my stomach (denoting nausea): :-!
Drunk or embarrassed (meaning either “I’m drunk” or “you’re drunk”): :*)
You are a deer: E:-) or 3:-)
You're a clown: *:O)
Heart 💓:<3
Text designation of the “rose flower” emoticon 🌹: @)->-- or @)~>~~ or @-"-,"-,---
Carnation: *->->--
Old joke (meaning button accordion): [:|||:] or [:]/\/\/\[:] or [:]|||[:]
Krezi (means “you’ve gone crazy”): /:-(or /:-]
Fifth point: (_!_)

What do horizontal (Japanese) symbolic emoticons mean?

Initially, it so happened that most of the text emoticons that were invented and became widespread had to be deciphered as if “tilting the head to the side.” However, this is not entirely convenient, you will agree. Therefore, over time, their analogues began to appear (also typed from symbols), which did not require virtually or actually tilting the head to the side, because the image created by the symbols was located horizontally.

Let's take a look what do the most common horizontal text emoticons mean?:

(joy) is usually indicated: (^_^) or (^____^) or (n_n) or (^ ^) or \(^_^)/
in symbols denoted as: (<_>) or (v_v)
The following symbols mean different things: (o_o) or (0_0) or (O_o) or (o_O) or (V_v) (unpleasant surprise) or (@_@) (meaning “You can be stunned”)
Emoticon meaning: (*_*) or (*o*) or (*O*)
I'm sick: (-_-;) or (-_-;)~
Sleeping: (- . -) Zzz. or (-_-) Zzz. or (u_u)
Confusion: ^_^" or *^_^* or (-_-") or (-_-v)
Anger and rage: (-_-#) or (-_-¤) or (-_-+) or (>__
What does fatigue mean: (>_
Jealousy: 8 (>_
Distrust: (>>) or (>_>) or (<_>
Indifference: -__- or =__=
This emoticon text expression means: (?_?) or ^o^;>
Value close to: (;_;) or (T_T) or (TT.TT) or (ToT) or Q__Q
What does winking mean: (^_~) or (^_-)
Kiss: ^)(^ either (^)...(^) or (^)(^^)
High five (means friend): =X= or (^_^)(^_^)
Carrot Love: (^3^) or (*^) 3 (*^^*)
Apology: m (._.) m
Greedy emoticon: ($_$)

Naturally, on many blogs and forums it has long been possible to add emoticons in the form of pictures (from ready-made sets), but many still continue to use text emoticons, because they have already gotten their hands on it and there is no need to find the right one in the catalog picture.

If you want to know what this or that set of characters that is a text emoticon means, write about it in the comments. Maybe the whole world will figure it out...

Good luck to you! See you soon on the pages of the blog site

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Hello, Kirill.

I think you have seen a special table in the ophthalmologist's office, which depicts 12 rows of some letters of various sizes. This table is usually used to test distance visual acuity. To test vision, the patient sits 6 meters from the table, closes one of the eyes in turn, and the doctor asks the patient to name the letter indicated by him. If a person sees all the letters that are located in the 10th row of the table, then his visual acuity is 1.0. In the case when the patient is able to distinguish letters only in the 9th line of the table, his vision is 0.9, etc.

Naturally, visual acuity of 0.9 is no longer normal, because your eye is no longer able to see what a person with visual acuity of 1.0 can see. Of course, this situation is not critical, because... vision is not very much reduced. However, a drop in visual acuity may be a warning sign. The point is that children aged 10 to 15 years often experience a sharp decline in vision. This occurs due to the rapid growth of the child’s body and the impact of heavy stress on the eyes. Unfortunately, vision loss is not always caused by age-related changes in a child’s body. This may be due to the impact of various unfavorable factors on the child’s body.

In some cases, decreased vision is caused by reasons that, at first glance, have nothing to do with the eyes. For example, vision may deteriorate in cases where there are lesions of the spinal cord and central nervous system, liver diseases, slagging in the body, adverse effects of environmental factors, infectious diseases, etc. Another reason for decreased visual acuity can be fatigue not only of the eyes, but of the entire body as a whole.

Naturally, when a child experiences a decline in vision, the obvious question arises as to what needs to be done to prevent vision from deteriorating even further. Of course, the best option is to visit an ophthalmologist, who can give advice on how to prevent further loss of vision. In cases where simple recommendations do not help to cope with decreased vision, special treatment may be prescribed, and sometimes surgical operations are indicated.

Now I will tell you about the main recommendations that can help a person maintain his vision. Firstly, it is worth paying attention to where the student’s desk is located and where the light falls on it. The desk should be located in a bright place, but it is not advisable to place the desk right next to the window, because direct sunlight is very harmful to the eyes. It is advisable to move the table away from the window so that the light from the window falls on the left if the child writes with his right hand (and vice versa, the light falls on the right if the child is left-handed). If we talk about additional lighting, then on the desktop you can install a table lamp in the far left corner of the table. In this case, you need to take into account that its light does not fall directly into your eyes. The light of the lamp should be soft, it should not be too bright, and its shade should provide a soft dispersion of the rays. Under no circumstances should you read in the dark, do your homework only with a table lamp, and so on.

Secondly, one of the reasons for decreased vision may be a lack of vitamins in the body, so it is necessary to monitor proper nutrition and regularly consume foods rich in vitamins (especially vitamins A, B, C). It is believed that the most beneficial for vision are carrots, blueberries, spinach, berries and fruits, dried fruits, various vegetables, and dark chocolate.

Naturally, watching TV, as well as time spent at the computer, can have a very negative impact on the child’s vision, because the eyes become very tired. In general, school-age children are not recommended to watch TV more than 1.5 - 2 hours a day, and it is advisable to divide this time into several viewing sessions. It is also worth noting that you should not watch TV in the dark, because a sharp change in light and shadow is very unfavorable for the eyes, and the distance from a person to the TV should be at least 2 meters.

The time you work at the computer should also be limited, because... Children are not recommended to spend more than 1.5 - 2 hours a day in front of the monitor, while sitting at the computer continuously can be no more than 20 minutes (for the age of 10-11 years). If we talk about the total time spent on the computer and TV, it should also not exceed 2 hours. In between working at the computer or watching TV, you can do special exercises that help relieve eye strain.

After the examination, the ophthalmologist said that your vision is minus one, three or even six? The minus in this case means myopia (that is, myopia), and the number indicates the degree of distortion in the visibility of the images. With vision of minus one, a person has difficulty seeing objects at long distances, and with minus seven – literally in front of him. With minor deviations from the norm, vision can still be restored, but if it is severely negative, all that remains is to correct it with lenses/glasses or undergo surgery. Read on to find out where myopia comes from, what diseases can cause it, and what needs to be done to treat and prevent the disease.

Symptom Definition

Minus vision is myopia, that is, with this disease, a person has difficulty seeing objects in the distance. There are three types of myopia:

Myopia can be low, medium and high - accordingly, distortions in the visibility of distant images will also vary.

Myopia occurs when the focus of the image that a person sees is located in front of the retina (if it is behind the retina, farsightedness develops). With myopia, it is difficult for a person to see objects in the distance without glasses, but he can see well near. Ophthalmologists prescribe wearing glasses with concave lenses - they move the focus to the center of the retina, and the visibility of distant objects improves.

Concave lenses are designated as a minus, and convex lenses as a plus.

The main symptoms of myopia:

poor visibility of objects in the distance;
blurred image contours;
blurry picture;
good vision up close.

By the way, myopia is one of the most common ophthalmological diseases.

Causes

In modern ophthalmology, there are two causes of myopia - ophthalmological and accommodative.

Vision can deteriorate for one of two reasons:

If your vision is poor, have regular checkups with an ophthalmologist. Particular attention should be paid to children - while the eyes are developing and the load is constantly increasing, a sharp drop in visual acuity can occur at any time.

Regular preventive examinations in childhood by an ophthalmologist help to avoid a lot of problems in the future.

Possible diseases

The following chronic diseases can lead to the development of myopia:

pathologies of the musculoskeletal system (scoliosis, valgus, flat feet, etc.);
allergic and infectious diseases (measles, scarlet fever, diphtheria);
infectious hepatitis;
tuberculosis;
diseases of the nasopharynx and oral cavity;
rickets.

A general decrease in immunity plays an important role - if the body’s defenses have fallen, myopia may develop.

Diagnostic methods

You can accurately determine the degree of myopia using an ultrasound machine (it shows the degree of elongation of the eye). Glasses or lenses are prescribed only after diagnosis.

Carrying out an ultrasound examination of the eyes

Treatment

The main methods of treating myopia:

Good to know. Eye exercises give very good results in the treatment of myopia, but only in the early stages of the disease.

Special exercises

Regularly performing the exercises described below gradually leads to an improvement in the condition of the eye muscles - they become resilient and strong:

Gymnastics for the eyes for myopia has a pronounced therapeutic effect by activating the blood supply to the eye tissues and training the muscles.

Vitamins

Pharmacies offer a wide selection of vitamin complexes for the eyes. They are taken in courses, usually twice a year for 30 days. Instead of synthetic vitamins, you can use natural ones - dairy products, sea fish, vegetables, carrots and blueberries are very beneficial for the eyes.

Hardware treatment

Hardware treatment of myopia involves the use of special equipment. An integrated approach gives maximum results. First, the doctor examines the patient, identifies the causes of myopia and the mechanisms of its progression, and diagnoses possible complications (usually degenerative changes in the retina or fundus tissue). As a rule, hardware treatment is combined with optical and drug treatment.

Glasses and lenses

Wearing glasses and contact lenses is the most common method of conservative treatment of myopia. Night wear lenses of the Paragon CRT type allow you to correct vision during sleep and are most effective in childhood and adolescence. Regular glasses and contacts are prescribed by the doctor after diagnosing the deficiency. The main disadvantage of optical treatment is that it only helps while you are wearing correctors.

Selection of optical lenses

Orthokeratological lenses (night wear) are used quite rarely; they are a real salvation for athletes.

Operations

A 100% sure way to forget about myopia is surgery. Types:

The most popular method of laser correction of myopia is Lasik. With high degrees and progressive nature of myopia, excimer laser correction is impossible. First, the scleroplasty technique is used, and a few years later laser correction is done.

Prevention

Do you want to prevent the development of myopia? In this case:

Pay enough attention to eye hygiene - that is, a set of rules that reduce the risks of pathological changes in the structure and functions of the eye. This is “healthy” writing and reading (in normal lighting, at a safe distance), regular breaks while working at the computer.
Do gymnastics - it is simple and perfectly strengthens the accommodative muscle.
Treat your eyes with care - do not overstrain them, use moisturizing drops, wear sunglasses in the summer.
Adjust your diet – your diet should have enough minerals and vitamins.

If you want to support your eyes, take vitamin A from time to time.

The above preventive measures are an effective remedy for the development of myopia and a sure way to avoid future vision deterioration if the disadvantage is still small.

Quarter lenses are contact lenses for three months, and how to wear them, see the link

What helps with stye on the eye: medications and folk remedies are presented here.

Polinadim eye drops with instructions for use are described here.

Video

Conclusions

Minus vision is myopia. The degree of deterioration in the visibility of distant objects can vary, so the doctor makes more accurate diagnoses like “minus one” or “minus five.” The reasons for the development of myopia are accommodative and anatomical. Treatment of the pathology is carried out using vitamin preparations, special gymnastics, and surgery.

Also read about what symptoms accompany astigmatism and how to treat this pathology, and what to do if a child is diagnosed with strabismus.

What are the vision restrictions for obtaining a driver's license?

Nowadays, a car is no longer considered a luxury item, but a means of transportation. But even if you buy a personal car or receive it as a gift, you will not be able to get behind the wheel without obtaining a driver’s license. Everyone knows that to obtain a driving license, it is important not only to undergo practice and study theory, but also to pass a medical examination. One of the doctors you will need to visit will be an ophthalmologist who will check your vision. If you have any vision problems or eye diseases, this will be a contraindication for issuing a permit. What are the vision restrictions for obtaining a driver's license?

What does an ophthalmologist check?

When passing a medical commission, a mandatory item is the permission of an ophthalmologist. This document is considered the most important, because road safety depends on the driver’s vision. In this regard, doctors are very careful about passing a vision examination to obtain a driver's license.

After visiting an ophthalmologist, an examination of the visual organs begins in the following areas:

checking visual acuity (how well a person sees);
determination of the level of color sensation (detection of abnormalities in eye functions);
study of horizons (how fully a person sees in his field of vision);
eye diseases (if any).

Pay attention! Even if some deviations are present, this does not mean that it is prohibited to drive vehicles.

If your vision is low, your doctor may choose glasses or contacts. If any eye diseases are identified, he will advise how to cure them.

In situations where the eyes often get tired, the ophthalmologist can prescribe special eye exercises, which, after a long and constant time, can help improve vision.

Important! If the future motorist already wears glasses or long-term optics, then these products must be brought with him to an appointment with a specialist.

What should be the visual acuity?

Visual acuity is considered a very important indicator during the examination, and it mainly determines whether you will be given a visual permit for a driver’s license.

This indicator is determined using the Sivtsev table, familiar from childhood, which depicts letters from large to small sizes. Sharpness is checked separately for each eye. At first they do this without glasses, and then, if they have them, they determine it with them.

Vision is considered ideal when a person was able to read the 10th line of the table below. If this does not work out, it is suggested to read line 9 or 8 from the bottom (depending on the situation).

So at what indicators is there a vision limitation for obtaining a license?

A driver's license will not be issued in the following situations:

If the difference in the acuity of the two eyes is greater than 0.4.
For myopia and hypermetropia of increased degree, when it is necessary to wear glasses or lenses with diopters of more than 8.0.
In the presence of astigmatism, and the sum of the sphere and cylinder is more than 8.0 diopters.
If one eye is blind, and the acuity of the second is less than 0.8.
When using glasses or lenses, the optical power of which, as a rule, differs by more than 3 diopters.

Color perception and horizons

Testing the future motorist for color perception, that is, the perception of the color gamut of light, is also considered an obligatory step. When passing a medical commission, doctors determine a person’s ability to distinguish the colors of a traffic light, which is very important for driving on the roads. For such a survey, the Rabkin table is used.

Ophthalmologists distinguish three types of people based on color perception:

Trichromats (normal).
Protoanopes (there are deviations in the red spectrum).
Deuteranopes (have disturbances in the green spectrum).

If an indicator such as color vision is abnormal, then this condition cannot be corrected with glasses or lenses, and cannot be cured. And, of course, such violations are a visual limitation for obtaining a driver's license.

Also, admission will not be allowed if the person has a narrow outlook. It is determined when diagnosing extreme narrowing of vision. Its indicator should not be more than 20º.

Like color blindness, visual field impairment cannot be corrected or treated in any way. This condition is very rare and, as a rule, indicates the presence of very serious eye diseases.

Eye diseases - driving bans

If visual acuity is reduced by a small amount, and color sense is normal, but the motorist has eye diseases, then the doctor will not allow you to attend driving courses. Such eye ailments include:

retinal detachment;
cataract;
pathological disorders of the lacrimal sac;
glaucoma.

If you have the above diseases, even acceptable vision for a driver’s license will not help in obtaining a certificate of permission. This is due to the fact that such eye diseases are not treated conservatively and by selecting the right optics. Their therapy can only be effective after surgery. Only after this method of treatment, after a certain time, namely not earlier than 3 months, will not one specialist, but several, decide on permission to drive a car.

Conclusion on the topic

Driving a vehicle is a very serious and responsible task. To avoid any emergency situations on the roads that could harm human life and health, it is important to responsibly undergo a medical examination before driving. Therefore, when you decide to drive a car, check that your vision is in perfect order. And an ophthalmologist will help you with this. Take care of yourself!