## A hidden threat Sunlight consists of different types of rays, but the most dangerous for the eyes are ultraviolet rays — specifically UV-A and UV-B. These rays can damage the tissues of the eye, from the cornea to the retina. Unlike a sunburn of the skin, the negative effects of excessive sun exposure to the eyes accumulate over time and may not show up immediately. The degree of damage depends on the wavelength of the UV rays, as well as the duration, intensity, and surface area of exposure. Frequent and prolonged exposure to sunlight without eye protection increases the risk of the following conditions: - Photokeratitis: a sunburn of the cornea that causes stinging, redness, tearing, and temporary vision impairment. - Cataracts: clouding of the lens that can develop more quickly with chronic UV exposure. - Macular degeneration: damage to the central area of the retina, a common cause of age-related vision loss. - Pterygium: thickening of the conjunctiva, which can grow onto the cornea and impair vision. ## Who is most at risk? Sunglasses are beneficial for everyone, but especially important for===: - People with sensitive eyes. - Children — their lenses are more transparent, so UV rays penetrate deeper. - Those who've had eye surgery (for example, cataract removal). - People who spend a lot of time outdoors, especially near water or in the mountains. If you think sunglasses are only necessary in sunny summer weather — you're mistaken. Even on cloudy or cold days, UV levels can still be high. Snow reflects up to 80 % of UV rays, intensifying exposure and increasing the risk of corneal burns. During colder seasons, sunglasses also protect the eyes from dry air, irritation, and wind. > By the way, there are soft contact lenses with built-in UV filters. ## How good sunglasses differ from regular ones The most important feature of sunglasses is UV protection. Not all sunglasses include this feature. To know which sunglasses will actually protect your eyes, it's important to check the labeling. - UV: indicates some level of protection, but doesn’t specify from which types of rays or to what extent. - UVA and/or UVB: indicates protection from specific types of UV rays. - UV + numbers: show the maximum wavelength the glasses can block. The best option is UV 400, which blocks both A and B type rays. - UV 100 %: means full protection against ultraviolet radiation. You should also consider the lens tint category, which determines how much visible light passes through.There are four main categories: __Category 1:__ light tint. Usually colorful lenses (pink, blue, etc.), often worn as fashion accessories. They can offer full UV protection but won’t shield your eyes from bright light. __Category 2:__ moderate tint. Good protection from light while maintaining comfortable visibility. Ideal for daily wear in sunny weather. __Category 3:__ dark tint. Suitable for the beach, outdoor activities, and strong sunlight. May be too dark for urban environments. __Category 4:__ very dark tint. Allow less than 10 % of light to pass through. Not recommended for driving; typically used in extreme conditions like mountaineering or on snow or water. > Sunglasses with dark lenses but no UV protection are more dangerous than not wearing sunglasses at all. Dark lenses cause the pupils to dilate, allowing more harmful rays to reach the eye. ## What kind of sunglasses do children need? Little ones need sunglasses from the moment they start walking independently — around one year of age. The selection criteria are mostly the same as for adults, but with a few extra considerations: - The frame material should be durable and flexible. - There should be minimal small parts in the frame. - They should be made from medical-grade plastic or polycarbonate, which are lightweight, sturdy, and safe. - Lens colors should be neutral such as green, gray, or brown. > Children with vision problems should be fitted for sunglasses with the help of an ophthalmologist. ## Tips to remember - Look for sunglasses labeled "100 % UV protection" or "UV 400". - For everyday use, moderately tinted lenses (category 2) are best. - Buy sunglasses only from optical stores or specialized retailers. - Wide temples or oversized frames help block rays from the sides. - It makes sense to wear sunglasses even on cloudy days.