Ultraviolet radiation from the sun can cause cumulative damage to your eyes as you age, but you can protect your vision by wearing sunglasses every day, even in cloudy weather. Here’s what you need to know about choosing the best sunglasses to prevent age-related cataracts and other eye problems over time.
UV Radiation and the Aging Eye
As we get older, our eyes undergo physiological changes that can cause vision problems and eye diseases such as age-related macular degeneration and glaucoma. Ultraviolet light from the sun carries three types of radiation, UVA, UVB (which causes photoaging and wrinkling of our skin), and UVC rays. Since UV light carries more energy than visible light, it can do greater damage to our eyes. As we age, the damage simply has more time to accumulate: a cataract, (cloudiness of the lens) for example, is believed to be caused by many years of exposure to bright sunlight.
Sunglasses designed to block 100% of UVA and UVB rays will protect your eyes against this cumulative damage.
Does Lens Darkness Matter?
While very dark lenses might seem to offer greater protection, the darkness the lens only affects visible light, not ultraviolet light.
Natalie Hutchings, Associate Professor at the University of Waterloo’s School of Optometry and Vision Science, says dark lenses can actually cause the pupil of your eye to get larger to let in more light, making UV protection even more important.
“Degree of darkness and lens color or tint are not the factors which protect your eyes,” she tells me. “It’s crucial to choose glasses which block 100% all of the UV light, both UVA and UVB. This protection can be a function of the material the glasses are made of, the thickness of the material, or it may be a coating on the lens — even in lenses without any color or tint at all. It’s the 100% UV blockage you should look for on the label, since you can’t tell whether they have it, just by looking at the glasses.”
Tips for Choosing the Best Sunglasses
According to the American Academy of Ophthalmology (AAO), the best sunglasses offer:
- 100% UV protection
- High optical quality (lenses are free of manufacturing defects like bubbles or waves that could bother your eyes
- Scratch-resistant lenses
- A larger frame that offers more coverage of eye area
In addition, pick sunglasses that are comfortable and fit your face properly, because you’ll be more inclined to wear them. As the the skin around the eyes are thin and sensitive to light, larger sunglasses and/or wrap-around sunglasses covering not only the eyes but the skin around the eyes may help prevent against aging changes and melanoma.
The Effectiveness of Polarized Lenses
Hutchings says polarized lenses work in visible light (not UV rays), by blocking out polarized light that is reflected off of a horizontal surface like snow, water or a hot road. Consider polarized lenses if you ski, live near water, or find them more comfortable while driving. While these lenses are usually more expensive, you may find you prefer them if you are sensitive to glare and/or have lighter color eyes.
When You Should Wear Sunglasses to Protect Your Eyes
The AAO recommends wearing sunglasses anytime you are outdoors, particularly in the summer, when the level of UV radiation is triple that of other times of the year. In addition, you should take care to wear sunglasses when on the water or in the snow, when light rays are reflected.
Older adults with cataracts and those who are more light-sensitive may find they need to wear sunglasses more often than they used to, says Natalie Hutchings, because light passing through the cornea and lens is scattered to a greater degree. This scattering effect can be distracting and annoying, but it is alleviated with the use of sunglasses, especially larger ones that block light coming in from the sides.
If you are finding that you are more light-sensitive lately, or seemingly more than before, see your eye doctor, as it could be a sign of a problem.
Wearing Sunglasses After Cataract Surgery
During cataract surgery, a new intraocular lens (IOL) is inserted to replace the old cloudy lens. Most intraocular lenses now absorb UV light. If you had your cataract surgery some time ago, your lens may not absorb UV light, and you should wear sunglasses that offer that protection. The AAO recommends even people with UV-absorbing lenses after cataract surgery wear protective sunglasses.
Other Ways to Protect Your Eyes From the Sun
Sunglasses offer just one form of protection for aging eyes. Health Canada and other agencies advise also wearing a visor or wide-brimmed hat when you’re outdoors and avoiding times of brightest and most intense sunlight, such as summer days between the hours of 11 a.m. and 4 p.m. (when the UV index is highest).