Sunglasses Buying Tips
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There are no doubts that spending long hours in the sun without eye protection can damage your eyes. It can contribute to cataracts, macular degeneration and growths on the eye, including cancer. Based on studies that have been done, ophthalmologists recommend that you wear 99 percent and above UV-absorbent sunglasses and a brimmed hat whenever you’re in the sun for long periods of time.
What to Look for When Purchasing Sunglasses
All sunglasses are designed to protect our eyes from the sun’s harmful effects. Often the labels on sunglasses promise protection from ultraviolet light and other kinds of natural radiation.
Blocks 99 Percent of all Ultraviolet Rays
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Look for sunglasses that block 99 percent or 100 percent of all UV light. UVB radiation is considered more dangerous to the eyes and skin than UVA radiation. Some manufacturers’ labels say “UV absorption up to 400nm.” This is the same thing as 100 percent UV absorption.
Quality of Sunglasses
Some nonprescription glasses are ground and polished to improve the quality of the lenses. Nonprescription lenses that are not ground and polished will not hurt your eyes. But distortion maybe uncomfortable.
To check the quality of nonprescription sunglasses, look at something with a rectangular pattern, such as floor tile. Hold the glasses at a comfortable distance and cover one eye. Move the glasses slowly from side to side, then up and down. If the lines stay straight, the lenses are fine. If the lines wiggle, especially in the center of the lens, try another pair.
Polarized
Polarization has nothing to do with UV light absorption, but many polarized lenses are now combined with a UV-blocking substance. Check the label to make sure the lenses provide maximum UV protection.
Polarized lenses cut reflected glare — sunlight that bounces off smooth surfaces like pavement or water. They can be particularly useful for driving and fishing.
Lens Darkness
The color and the degree of darkness do not tell you anything about the lenses’ ability to block UV light. But if you use the glasses for very bright conditions, choose a darker lens.
Photochromic
Photochromic lenses may be good UV-absorbent sunglasses (again, the label must state this benefit), it takes time for them to adjust to different light conditions. Most of the darkening takes place in about half a minute, while the lightening takes about five minutes. Photochromic lenses come in a uniform or gradient tint.
Sunglasses That Blocks 90 Percent of Infrared Rays
Infrared wavelengths are invisible and produce heat. Sunlight has low levels of infrared rays, and the eye tolerates infrared well. Some sunglass manufacturers make health claims for their products based on infrared protection, but research has not shown a close connection between eye disease and infrared rays.
Contact Lens Wearers
Contact lenses by themselves may not protect your eyes from UV light. There are contact lenses available with UV protection. If you do not have contact lenses that absorb UV light, you need to protect your eyes with sunglasses.
The best sunglasses offer 100 percent UV absorption, are of the best optical quality and are impact resistant. For general outdoor activities, proper sunglasses are key to protecting your eyes from sun-related damage
