subject: Why Do We Need Sunglasses? [print this page] In hot summer days, we always have to wear sunglasses to protect our eyes. But if the sun doesnt bother my eyes, are you necessary to wear sunglasses? Obviously, the answer is yes! The sun has damaging UV (ultraviolet) rays that can cause photokeratitis, pingueculae and permanent retinal damage.
Lets have a clear idea of UV rays. UV Ultraviolet (UV) rays are located just past the violet portion of the visible light spectrum; sunlight is the main source. UV light is broken into three different types: UVA, UVB and UVC.UVA has longer wavelengths and passes through glass easily; experts disagree about whether or not UVA damages the eyes. UVB rays are the most dangerous, making sunglasses and sunscreen a must; they don't go through glass. UVC rays do not reach the Earth because its atmosphere blocks them.
Most people think that they're at risk only when they're outside on a sunny day, but UV light can go right through clouds, so it doesn't matter if the sky is overcast. The sun's rays are strongest between 10 am and 2 pm. Glare and reflections can give you trouble, so have your sunglasses ready if you'll be around snow, water or sand, or if you'll be driving (windshields are a big glare source).
You must wear sunglasses to prevent damage to your eyes. While some contact lenses provide UV protection, they don't cover your whole eye, so you still need sunglasses. Look for sunglasses that protect you from 99 to 100 percent of both UVA and UVB light. This includes those labeled as "UV 400," which blocks all light rays with wavelengths up to 400 nanometers.
Since sun damage can occur regardless of the season or weather, and the effects are cumulative, wearing sunglasses everyday is important. Sunglasses are significant for each of us to our eye protection.
