Damage to Your Eyes 
Acute eye damage may be caused from single outings on very bright days. Excessive exposure to ultraviolet light reflected off sand, snow, water or pavement can damage the eye’s surface. Similar to a sunburn, eye surface damage usually disappears within a couple of days, but may lead to further complications.
Long-term exposure to UV radiation (“sunburn rays”) may contribute to the development of various eye disorders, such as macular degeneration, the leading cause of vision loss among older Americans, and cataracts, a major cause of visual impairment and blindness around the world.
What to Look For in Sunglasses
There are thousands of sunglasses available today. Below are the important features to look for to ensure your eyes are protected.
UV Coating: Plastic and glass lenses absorb some UV light; however, the UV protection in the plastic and glass lenses can be improved by adding a special coating to the lenses. Polycarbonate lenses offer 99 percent UV protection.
Some labels read “UV protection up to 400nm” – this means 100 percent UV absorption. Be careful of purchasing sunglasses that state they “block UV” without saying how much, they need to block 99 to 100 percent of UV rays.
Mirror Coating: Mirror finishes are just thin layers of various metallic coatings on ordinary lenses. Although mirror coating reduces the amount of visible light reaching your eyes, do not assume they will protect your eyes from UV radiation. Check the label to ensure the sunglasses block 99 to 100 percent of UV rays.
Gradient Tint: Gradient lenses are permanently shaded from top to bottom or from top and bottom toward the middle. There are single gradient lenses (dark on top and lighter on the bottom) and double gradient lenses (dark on top and bottom and lighter in the middle). The single gradient lenses are useful for driving because they reduce glare while allowing you to see clearly, but are not good for sports. Double gradient lenses are the opposite – they are better for sports where light reflects up off the water or snow, but not for driving, because they make the dashboard appear dim. Tinting has little to no effect on UV protection.
Color and Darkness: The color and degree of darkness do not tell you anything about the lenses ability to block UV rays. UV coating itself is colorless. Color choice is a personal decision based on your needs and wants. Each color has different qualities to consider:
- Green: offers some color contrast with little or no color distortion (best for multi-use)
- Gray: flat color offers no contrast, along with no color distortion
- Brown: offers very high contrast and depth perception, but it distorts color - optimum for object definition
- Yellow: optimum for object definition, but creates a harsh visible light
- Vermillion: best on water to define water from other objects, but has the worst color distortion
Your Eye M.D. can provide information on sunglasses and UV protection, as well as eye health and safety.
If you would like more information on sunglasses and UV safety, please visit the American Academy of Ophthalmology’s public information website at www.medem.com/eyemd.
Source: American Academy of Ophthalmic Executives
