Sunglasses: Frequently Asked Questions

1. If the sun doesn't bother my eyes, do I still need to wear sunglasses?

Yes. The sun has damaging UV rays that can cause photokeratitis, pingueculae, and permanent retinal damage.

2. What exactly are UV rays?

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.

3. When do UV rays affect my eyes?

Most people think that they're only at risk 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).

The following put you at additional risk: sunlamps, tanning beds and parlors, photosensitizing drugs, and living at high altitudes or near the equator.

Read more about UV light.

4. Can certain medical problems increase my risk for damage from UV rays?

Yes. People with cataracts (or who've had cataract surgery), macular degeneration, and retinal dystrophies should be extra careful. Read more about these conditions in our Eye Problems and Diseases section.

5. What are my options to prevent damage to my eyes?

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 percent 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. (This covers all of UVA and UVB rays.)

Also, you may want to consider wraparound sunglasses to prevent harmful UV rays from entering around the frame.

6. What are the different kinds of lenses that are available?

With so many lenses available, it is difficult to find ones that will protect your eyes if you don't know what each one will do.

Blue-blockers block blue light and usually have amber lenses. Researchers are still unsure whether or not blue light is harmful, but these are popular among skiers, hunters, boaters, and pilots.

Both polarized lenses and anti-reflective coating cut reflected glare. Polarized lenses in particular are popular with those who play water and snow sports. Read more about polarized lenses and anti-reflective coating.

Mirror-coated lenses limit the amount of light entering your eyes, so you're more comfortable.

Gradient lenses are tinted from the top down, so that the top of the lens is darkest; they're good for driving. Double gradient refers to lenses that are also tinted from the bottom up: the top and bottom are darkest and the middle is clear (or close to it); double gradients are not very useful for driving, because they make it difficult to see the dashboard.

Photochromic lenses adjust their level of darkness based on the amount of UV light they're exposed to. Read more about photochromic lenses.
 

7. What about sunglasses blocking infrared rays?

Infrared rays are located just past the red portion of the visible light spectrum. While some experts believe that infrared light can be harmful in certain situations (such as being near large bodies of water or at high altitudes), most feel that the sun's infrared rays do not pose a danger to the eyes.

8. Which lens color is the best?

Color is a personal choice and doesn't affect how well the lenses protect your eyes from UV light. Gray and brown are popular because they distort colors the least. Athletes may choose other tints for their color-enhancing properties; for example, yellow lenses are popular with skiers and target shooters because they work well in low light, reduce haze, and increase contrast for a sharper image.

Read more about lens color.

9. Are impact-resistant lenses necessary?

The U.S. Food and Drug Administration requires all sunglasses to be impact-resistant. However, those who play sports or wear sunglasses on the job might want to consider ultra-impact-resistant polycarbonate.

Read more about polycarbonate.

10. Do I still need those "UV Protective" sunglasses if my lenses are real dark?

Yes! Most people believe that the darkness of the lens is what protects their eyes. The degree of darkness has no effect on UV rays. For adequate protection, you need to buy sunglasses that indicate they block 100 percent of the sun's UV rays.

11. Are the more expensive sunglasses of better quality?

Not necessarily. While expensive sunglasses are usually high quality, you can also get a good pair for under $20 if you're a careful shopper. Just make sure to check that they provide adequate protection from UV light and are free of distortions.

You can also take them to your eyecare professional to have the lenses metered to determine the amount of UV that passes through the lenses. That way you can be sure that you are getting the most from your sunglasses.

12. Children don't need sunglasses, do they?

Children are at particular risk because they're in the sun much more than adults, and their eyes are more sensitive as well. UV damage is cumulative over a person's lifetime, which means you should begin protecting your child's eyes as soon as possible.

Most parents would not allow their children to go outside without shoes, yet many seem unaware of the need to protect their children's eyes.

Read more about children's sunglasses.

13. I wear glasses. What options are available to me?

You can buy prescription sunglasses or glasses with photochromic lenses (which change from clear to dark) from your eyecare practitioner. Clip-ons are a less expensive option, and can be bought at the same time as your regular eyeglasses to perfectly match the frames. Magnetic attachments may also be available. Read more about prescription sunglasses and photochromic lenses.

14. Do those sunglasses for specific sports really make a difference?

Yes. Sports eyewear in general tends to be safer than regular sunglasses because the lenses and frames are made of special materials that are unlikely to shatter if struck and can give you the benefits of both sunglasses and protective eyewear. Also, certain lens colors can enhance your vision for certain sports; brown, for example, is popular with golfers because it provides nice contrast on those very green golf courses.

Read more about Performance/Sports Sunglasses and Sports Eyewear.