Bright sunlight is harmful to the eye - long-term consequences are "cataracts" and old-age blindness. The degradation of the ozone layer increases the dangerous ultraviolet radiation. Good protection of the eyes is therefore important because the eye remembers every ray of sunshine. According to experts at the University Hospital Bonn, good sunglasses are not just an unnecessary toy, they are also a must for children.
There are good reasons for not exposing your eyes to intense sunlight, especially in the summer months at sea and in the mountains. "In very strong light, we are often blinded despite built-in protective mechanisms of the eye, but this is often ignored by children, " says Professor. Frank Holz, Director of the Eye Clinic of the University Hospital Bonn. But by an excess of sunlight, the conjunctiva can inflame or even the cornea - acute consequence is the so-called snow blindness.
Children are particularly at risk from UV radiation
Especially children's eyes are particularly sensitive because the self-protection is not yet fully developed and light rays fall freely on the retina. This is particularly rich in so-called unsaturated fatty acids, which form free radicals by intense light. The retina is exposed to "oxidative stress".
Although the human retina has many protective factors, they can also be overused. Especially reading in the blazing sun is not advisable, because in this case the sunlight reflected from the white paper is always focused on a spot in the eye.
Damage to the lens and retina
"Permanent damage to the lens and retina that impair vision is painless and will not be noticeable for years, " says Professor Holz. Long-term consequences include a cataract, the so-called cataracts, or macular degeneration, a retinal disease in which the site of the sharpest vision is damaged. It is the leading cause of blindness in old age. However, to avoid permanent glare sensitivity of the eyes, sunglasses should not be worn constantly, inter alia, indoors.
Better quality sunglasses
Only sunglasses with high quality lenses that completely absorb dangerous UV rays effectively protect the eye. Only a lens with strong tint is dangerous on the other hand. Thus, the human pupil expands spontaneously through the obscuration. "If the right filter in the blue light and ultraviolet light wavelength range is missing here, even more harmful light is transmitted to the lens and retina, " warns Professor Holz.
So when buying sunglasses, you have to pay attention to quality:
- Quality features are the "UV-400" mark and the "CE" mark.
- Good glasses have no faults like air bubbles, give the environment undistorted and are scratch resistant.
- Yellow and green glasses distort the colors and especially the signal colors are not perceived well. In contrast, a brown or gray tint is ideal.
- A large glass protects against side light.
Children's glasses should have plastic lenses
Since glass splinters at break and so the risk of injury is high, children should wear sunglasses with plastic glasses. These also offer protection against possible "mechanical" accidents.
In addition to an effective UV filter, a good pair of children's sunglasses offers additional side protection against the scattered radiation from reflective surfaces. "Ideally, parents should consult the ophthalmologist to adjust the glasses and have the lenses tested for UV protection, " advises Professor Holz.
Sunglasses: Glare protection categories at a glance
- Category 0: 80 to 100 percent light transmission, very bright filter, for evenings
- Category 1: 43 to 80 percent light transmission, light to medium filter, well suited for overcast days and the city
- Category 2: 18 to 43 percent light transmission, dark universal filter, especially suitable for the summer, actually the perfect glare protection for our latitudes
- Category 3: 8 to 18 percent light transmission, very dark filter, well suited for southern climes, bright water areas, the beach and the mountains
- Category 4: 3 to 8 percent light transmission, extremely dark filter, too dark for traffic, suitable for high mountains and glaciers