On the threshold of summer season a lot of people think about purchasing of sunglasses. And of course the sellers become active: there are shops, on each step, where different models of any taste, colour, size… and price are presented. But, before buying, we should think, what do we know about the sunglasses and do our ideas correspond to the facts about them?
Myth 1. Sunglasses protect eyes from the sun and bright light, that positively effect eyesight.
NO First of all, such sunglasses must protect eyes not from the sun, but from the ultraviolet rays, which not only compose the part of direct sun light, but also are reflected from different surfaces. It is the reason to cause the irretrievable harm to eyesight. Secondly, not all dark or tinted glasses have right to be called “sunglasses”. Fashionable colour and design don’t determine the degree of protection, which is divided into 5 groups, do they? Glasses which pass 80%-100% rays are refered to first group and designed for cloudy weather. Glasses which pass 43%-80% rays, are refered to the second group and designed for non active sun. If the weather is clear, you can wear glasses of the third group, which pass 18-43% ultraviolet. The specialists recommend to wear glasses of fourth group(8-18%) in the summer, and extreme sport in mountains and water seekers can’t do without glasses with protection of the fifth group.
Myth 2. The darker glasses, the better.
NO Protective properties of the glasses don’t depend on degree of glass darkness, but on the material, which the lenses are made of. And by the way, if glasses are just tinted and don’t provide any protection, that may cause harm to eyesight. The sole reaction of the pupil to the light - is narrowing. And wearing dark glasses, we artificially lull the vigilance: the pupil reaction to insignificant intensity of the light is widening. Therefore, more ultraviolet rays are taken by retina, as if you don’t wear glasses. So, the main characteristics, which sunglasses must have is having high quality filter, protecting eyes from redundant sun light and harmful influence of ultraviolet emission, and the degree of darkness is on taste business.
Myth 3. Only in summer you should wear sunglasses.
NO In sunny day only 9-17% of ultraviolet rays reflect from the beach sand, but from the snow-85%. That is why, in mountains where there is a lot of snow, you can’t do without special glasses. And also in winter in the town it wouldn’t be too many.
Myth 4. Sunglasses help to avoid appearing of the wrinkles.
YES Bright sun or light patches make us squint, what cause appearing of mimic wrinkles on the forehead and crow’s feet near eyes. Glasses let eyes relax, and it significantly reduces loading to the skin, in turn, prevents appearing of the wrinkles.
Myth 5. Sunglasses help to protect eyesight.
YES The main reason of age eyesight worsening is dimness of cornea. Thin blood vessels appear between retina and eyeground, it causes dimness, and frequent and intensive influence of ultraviolet rays worsen it, that causes developing of cataract and increases the risk of blindness 10 times more. Only in 10% of cases the loss of sight occur during 6 months, in all other cases it occurs during many years. Therefore, wearing of sunglasses reduces the risk of eyes disease. Besides a big doses of C,E vitamin, beta-carotine, zinc copper prevent from developing of blindness.
Myth 6. To look at the sun through the sunglasses is absolutely safe.
NO Direct sunbeam can deprive eyesight less then in one minute- that is why it’s dangerous to look at eclipse without special devices. And usual, if to look at the sun too long, even if wearing sunglasses, it causes headache, and may cause temporary loss of sight, and in the same cases may cause serious problems. Bluntly speaking, you can get burn of retina. Particularly, this disease is found among that people, who watched solar eclipse without using of special devices, but through the simple sunglasses. But they don’t provide 100% protection from ultraviolet emission. Therefore, if to look at the sun too long, it may cause harm to retina, cornea and crystalline, even if they are hidden beyond the glasses.
Myth 7. Glass lenses are better then plastic ones.
NO Plastic lenses of good quality don’t yield to the glass ones. The last ones are more dangerous and heavier for eyes in the case of breaking, and the first ones are breaking easily. Therefore, the choice of glasses material is depend on taste and preferences.
Myth 8. The color of the lenses is importatnt.
YES Brown, grey and green lenses leave the natural colors of objects around, just changing their shades a bit. Red lenses affect nervous system, provoking too fast tiredness, that is why it isn’t recommended to wear it too long and often. Pink, yellow and orange lenses- increase contrast of image and reduce tiredness of eyes, preventing worsening of eye sight, though don’t fit for wearing in sunny days.
Myth 9. «Right» glasses should be big.
YES Glasses protect not only the pupils, but also skin, which is around the eyes. Therefore, glasses should have large frame and wide temples. And the distance between lens and eye shouldn’t be too big and cause discomfort.
Myth 10. Sunglasses are designed for adults and there is no need to wear sunglasses for children.
NO Organism builds its own mechanism only when reaches 20 years old age, and before it can be affected by external factors. Thus, children up to 10 years old get ¾ ultraviolet emission on their retina, and little babies- get the more. That is why sunglasses is more important for children, then for adults.
Author: Amina Kim. source - http://www.nationaltravel.com.ua/