An ophthalmologist answered 7 questions about vision

Hello everybody! My name is Lyudmila Panyushkina, I am an ophthalmologist and I also have a blog about eye health. In my work, I often come across myths and prejudices: some still believe that lingonberries help against eye diseases, and others are sure that vision deteriorates when wearing glasses.

Especially for the awesome.club, I will answer the most common questions on this topic and tell you how to maintain eye health for a long time. This post does not replace a consultation with a specialist and is not strictly scientific in nature, it is only intended to inform. So don’t forget to visit your doctor if you have any further questions or if you are experiencing any discomfort.

It’s hard to imagine modern life without computers and cell phones. Naturally, many are concerned about the following question: are electronic devices harmful to eye health?

Those who are forced to work for a long time with a computer sometimes complain of eyestrain and redness, and a feeling of having sand in the eyes. I will surprise you, but the light on the screen has nothing to do with it. Everything is due to non-stop work at a short distance (with a computer, documents, books or a phone), which is accompanied by insufficient blinking and, as a result, the development of dry eye syndrome. The problem is solved by observing a visual regimen and applying artificial tears (moisturizing drops).

Manufacturers of glasses for use in front of the computer (also called blue light blocking filters) use, as the main argument for promoting their products, the results of studies on the harmful effects of these rays from screens on the ocular retina. Blue light, according to some scholars, can cause irreversible visual changes and contribute to reduced vision.

But the fact is, these studies were done on animals, or they were experimental research on retinal cells in vitro. On the other hand, in general, experiments are carried out under extreme conditions (high doses of radiation), which no one would ever dream of reproducing in real life.

The effect of solar radiation on the human eye has also been studied under extreme conditions in people who stayed outdoors for a long time and rarely wore sunglasses. But sunlight is much brighter than any light used indoors, and the impact of blue radiation from a computer screen is much less than the cumulative effect of sun exposure.

Thus, so far, there are no studies confirming that prolonged exposure to blue light from device screens can cause irreversible changes in the human eye. Potentially, blue radiation can be harmful to the retina, but so far we don’t know what dose or duration of exposure can cause irreversible changes. So far, all studies in this area function more like advertising than anything else, and should not be taken as a parameter.

Keep in mind that blue light blocking glasses are not classified as medical devices and therefore do not require approval from the FDA, the strictest and most impartial body for overseeing the quality and safety of drugs and medical technologies. To use them or not is up to you.

It is also important to remember that blue light plays an important role in regulating “sleep-wake” cycles, and prolonged use of these blocking filters can lead to drowsiness during the day. In contrast, at night (approximately 2 hours before bedtime), it is recommended to avoid using digital devices or using special filters/programs that block blue light. As you may have noticed, this is not important for eye health, but is related to the quality and duration of sleep.

As we have seen, complaints of fatigue, discomfort, redness and dryness of the eyes do not arise from radiation from monitors, but from an incorrectly arranged work environment and infrequent blinking.

How to avoid the appearance of unpleasant symptoms? It’s a lot easier than it looks:

1. Respect the visual regime. For example, you can use the “20-20-20” rule: every 20 minutes, look for 20 seconds at an object that is 20 feet away (approximately 6 meters).
2. Make sure the diopters on your glasses are correct for computer work (after 40-45 years, distance lenses and computer glasses are different).
3. Use moisturizing drops to prevent dry eye syndrome.
4. When organizing your workplace, keep the following rules in mind:

The monitor should be about 50-60 centimeters away from the eyes, preferably about 20 centimeters below eye level. The height of the chair must be adjusted so that the feet are completely flat on the floor. Don’t forget to adapt the seat so that the children also follow these rules, especially if the computer is for common use by the family. Place the computer away from other light sources to minimize reflection on the screen. Dim lighting or use screen savers.

Many parents believe that TV is the main culprit in the development of myopia in children. Let’s see if this is really so.

Most children are born with farsightedness (ie, a slight positive diopter). As they grow, the eyeball stretches and lengthens and this condition is corrected without any intervention. If the eye grows too strongly, myopia appears. In this case, to see well, the child needs glasses with a negative value.

The causes of the appearance of myopia are still not fully known. The main role is assigned to heredity and external environmental factors. Among the latter, the most studied is the protective effect of sunlight on the risk of developing myopia. According to data from several important studies on the subject, walking outdoors can reduce the likelihood of the onset and progression of this condition.

What about short-distance ocular overload, which for a long time was considered the main cause of myopia? Modern research has not found a confirmation of this theory. Teenagers who watch a lot of TV or spend a lot of time using the computer have a high probability of developing or experiencing a progression of myopia, because they are deprived of sunlight and don’t spend time outdoors, not because of the devices themselves. . Although parents fear that children remain in front of screens, an ophthalmologist should not limit this. It is necessary to shift the focus of attention of parents from devices to organizing children’s leisure outside the home, in the fresh air.

Recommendations for limiting time in front of a screen or monitor are important not for the preservation of vision, but for the normal development of the child’s nervous system. The American Academy of Pediatrics recommends completely depriving children under the age of 2 of watching television and allowing them to use electronic devices for a very limited time. At an older age, it is necessary to limit total TV viewing time to 1 or 2 hours a day, and children aged 2-5 years are recommended not to use digital devices more than 1 hour a day.

Both adults and children, regardless of their skin type, are at high risk of eye damage from excessive exposure to UV radiation. It is important to remember that the damage from UV radiation is cumulative, it adds up over a lifetime. People with light iris color (blue or green) have a higher risk of developing oncological diseases such as iris melanoma or uveal melanoma.

UV radiation is not blocked by fog or clouds. You run the risk of getting more of it at midday, at high altitudes and when light is reflected off water or snow. Therefore, it is important to choose good sunglasses for yourself and your children.

Sunglasses must block 100% of harmful radiation. Choose those with the UV 400 mark and remember: the intensity of the lens color does not affect this parameter. Dark glass lenses can protect your eyes as well as clear ones. Glasses also differ in the level of light transmission. There are 5 categories of filters that are identified with numbers from 0 to 4 (usually this value is indicated on the inner surface of the glass, next to the CE mark). A filter marked “0” passes 80 to 100% of the light, one marked “4” passes 3 to 8%. In the city, to drive a car, for example, the first or second category filter will be sufficient, while for a trip to the beach or the mountains you will need a third or fourth one.

Another important detail: it’s better not to wear sunglasses than to wear ones without adequate UV protection. When exposed to the sun, our pupils reflexively shrink in diameter, which limits the harmful effects of UV radiation on the lens and retina. If you expose yourself to sunlight with glasses without a proper filter, the pupil will remain large, so that even more harmful radiation will penetrate the eye. If you have doubts about the quality of the lenses, do not buy.

Fruits and vegetables are necessary for the human body, but the benefit of some of them is clearly exaggerated: so, for example, the myth was born that lingonberries and carrots have a beneficial effect on vision. The former really contain vitamins and trace elementsbut this does not mean that its inclusion in the diet will protect from eye problems.

There is not a single study that can confirm the fact that this fruit is useful for human vision. With carrots the same thing happens. In general, eye diseases are rarely associated with a lack of vitamins, and a normal diet satisfies the nutritional needs of the eyes. Therefore, in case of problems in the area, it will be much more effective to turn to an ophthalmologist and not consume kilograms of vegetables, fruits and berries, hoping for a magical cure.

It’s a myth. Laser correction is a very safe procedure and its risks during execution are minimal.🇧🇷