Everywhere you look, sunglasses are for sale! Sunglasses are found in malls, street corner vendor stalls, drug stores, sports stores, and even supermarkets. Prices vary from $2 to $300. Did you know that a high percentage of the protecting effects advertised are mislabeled? How can you find a pair of sunglasses that really provides protection against the harmful effects of sunlight? Does a higher price mean the glasses are better?
Why Wear Sunglasses?
Sunlight is a nutrient, and it is essential for health. However, certain light rays have been shown to have a damaging effect on the eye. Specifically, ultra-violet A (320-400nm), ultra-violet B (286-320nm), and blue light (400-500nm) are suspect. Excessive sunlight can lead to an increased risk of cataracts and macular degeneration. Layers of pigment in the retina protect the retina and macula from damage from these wavelengths of light. However, exposure to UV and blue light thin the protective pigments causing damage from oxidative stress and free radical damage in the eye.
The eye takes in 9 to 18% of its exposure to UV radiation. Researchers have reported that there is no safe level of sunlight to avoid cataract risk.1 Furthermore, researchers have demonstrated that UV radiation causes oxidative stress and cell death that damages the retina and contributes to macular degeneration and other retinal conditions.2
The effect is to make the eye “age faster.” The light intensity of a bright sunny day makes the use of sunglasses necessary for comfortable vision. Damaging effects can be intensified as a result of glare off water, snow and windshields. All sunglasses worn outside should provide 100 percent UVA and UVB light protection. In addition, no more than 12 percent of visible light and between 2 to 5 percent of blue light should be allowed in.
Below are some guidelines in selecting the best sunglasses for your eyes.
How Dark Should the Sunglasses Lenses Be?
Darker does not necessarily mean better. You should find the darkest pair of eye wear that is comfortable on a sunny day and still allows you to see traffic lights. Ask if you can walk outside the store to try out the sunglasses, since the store’s artificial lighting makes it difficult to judge how effective the glasses actually are in sunlight. We do not recommend gradient lenses (those lenses that are dark on top and clear on the bottom) or mirror lenses. The reason for this is that since the tint is not uniform throughout lens, the pupils of the eyes which control the amount of light entering get stressed out.
What are the Best Sunglasses Lenses colors?
Best Colors for Protection:
- Orange-amber is the best and most effective color by far. Orange-amber lenses will block out 100 percent blue light. This is the best choice for patients with macular degeneration and cataracts. Some people have trouble tolerating them since they distort colors. Blue becomes black, and white becomes orange.
- Brown/Tan is the next best color. It blocks out most of the blue light and is easier to tolerate than the orange-amber color.
Colors Not Recommended:
- Gray/Green colors give the least amount of color distortion but do not give as much protection from blue light.
- Yellow enhances contrast and is favored by outdoorsmen on sunny days. Yellow does not provide adequate protection from blue light.
- Blue/Purple gives little protection for your eyes. A blue lens does not block out blue light.
What is the Differences Between Lens Materials?
Glass lenses are heavier and more susceptible to breakage but tend to scratch less easily. Note: Never use glass sunglasses for sports.
Plastic lenses are safer and lighter, but scratch more easily.
Polycarbonate is a special type of plastic that is more resistant to scratches and breakage, and should be used for sports.
What are Photochromic Lenses?
These are lenses that change color depending on the amount of sunlight and the temperature. They are available in both glass and plastic lenses. They are more effective in cold climates. The higher the temperature, the lower the degree of darkening.
What are Polarized Sunglasses?
This is a type of lens that only lets in light rays at a certain angle, thereby reducing glare. These lenses are most useful when light is reflected off flat surfaces, such as water.
What is the Best Lens Shape?
Wrap around lenses provide the best protection. Preferably the lenses should fit close to your eyes and be large.
Another Helpful Tip for Protection from the Sun
Wear a hat with a 3-inch brim in addition to your sunglasses.
Some Recommended Sunglasses Companies
The following are some companies that make excellent quality sunglasses which block out 100 percent ultraviolet and between 0-5 percent blue light. Ask the sales person for details since not all models provide this type of protection. Recommended companies include Gargoyles, Revo, Ray Ban, Serengiti, and Bolle.
Can Any Nutrients Help Protect You From the Sun?
Vitamin C, lutein, and alpha-lipoic acid have all been shown to help the eyes protect against ultra-violet and blue light damage.
About Dr. Grossman
Dr. Marc Grossman, Optometrist and Licensed Acupuncturist, is the co-found of Natural Eye Care located in New Paltz, New York and founder of Rye Learning Center in Rye, New York. Dr. Grossman has been in practice for 30 years, lectures internationally on eye disease, nutrition and alternative approaches, and is the author of 5 books on natural eye care including Natural Eye Care – Your Guide to Healthy Vision.