Here are some frequently asked questions about UV radiation from the sun and how sunglasses can protect your eyes from harm.
What are UV rays? UV stands for ultraviolet, a band of light spectrum invisible to the eye. Ultraviolet light consists of UV-A, UV-B, and UV-C rays. UV-C rays are stopped in Earth's atmosphere before they reach the eye, but UV-A and UV-B can both potentially damage most tissues of the eye.
How does UV affect unprotected eyes? UV rays can cause opacification and yellowing of the conjunctiva, which is the clear layer on top of the white part of your eye - if this continues to grow onto the cornea, it may become visually significant. UV rays can also cause proteins inside the lens to become opaque or cloudy, a condition known as cataracts. Cataracts can interfere with night vision, reduce your ability to see colors, and make reading difficult. UV rays can also cause retinal damage and increase risk of macular degeneration, and a temporary but irritating "sunburn" of the cornea called photokeratitis.
How do I know my glasses will protect my eyes? Choose glasses that claim to block at least 99 percent of UV rays - UV-A as well as UV-B. Look for label reading "UV 400," since this designation means that the glasses block UV rays as small as 400 nanometers, providing 100 percent eye protection.
What are polarized lenses? Polarized lenses are specially designed to filter out certain types of glare that tend to radiate from horizontal surfaces when sunlight bounces off of these surfaces, such as the ocean and other bodies of water. They are recommended for tasks such as boating, fishing, skiing, golfing, jogging, and driving. Most polarized lenses will bear a label identifying them as such.
What types of glasses can I choose from? We are able to provide you with a wide range of sunglasses options. In addition to prescription sunglasses, you may be happy with a non-prescription pair of clip-ons or wraparound glasses that simply fit over your lenses, or you can order glasses that have photochromic lenses, which darken when exposed to sunlight and lighten when indoors.
What additional types of protection should I consider? Wearing a hat is another method to protect your eyes from the sun. You may also want to think about getting a pair of UV-blocking contact lenses in your prescription; these lenses may be worn alongside a non-prescription pair of sunglasses for optimum eye protection.
For more information on choosing the right sunglasses, contact our office today.