Sunglasses are often thought of as primarily a fashion accessory, or a way to hide tired eyes. But in fact, they can play an important role in protecting your eyes, and the skin around them, from the damaging effects of ultraviolet (UV) rays emitted from the sun.
We spoke to Andrew Iwach, MD, clinical spokesperson for the American Academy of Ophthalmology and executive director of the Glaucoma Center in San Francisco, about the health benefits of wearing sunglasses and how to choose the right pair for you.
Why Sunglasses Matter
Regularly wearing sunglasses outdoors and in the car can help prevent conditions such as macular degeneration, cataracts, some cancers of the eye and eyelids, as well as photokeratitis (sunburn of the eyes), which can cause temporary pain, redness, blurry vision, and light sensitivity.
Sunglasses that wrap around the temples can additionally help to alleviate symptoms of dry eye and sensitivity associated with conditions like thyroid eye disease. And wearing a hat with a brim will block even more UV rays from reaching your eyes and eyelids.
Dr. Iwach emphasizes the importance of prevention when it comes to the skin around the eyes: "The skin around our eyes is particularly thin and delicate, so it's much easier to prevent cancer related to sun damage around the eye than it is to treat it."
Sunglasses can be just as important in the winter as in the summer: They can prevent snow blindness — a type of photokeratitis caused by UV rays reflecting off snow and ice. In any season, light reflecting off sand, water, or cement can have the same effect.
5 Tips for Choosing Sunglasses
Sunglasses are sold in all kinds of stores, from convenience stores to department stores to dedicated sunglasses retailers, and they don’t have to be expensive to offer good sun protection.
But if you have an eye condition or have any questions about which sunglasses are right for you, Iwach recommends shopping at an optical store with opticians on staff to help you make the proper sunglass selection.
1. UV Protection Is a Must
UV rays from the sun damage the eye's tissue directly and can also cause cancer in the skin around the eyes. For this reason, you want UV-blocking sunglasses as part of your sun protection whenever you are outdoors or in the car.
If you are not shopping at an optical shop with experts available to help you, look for sunglasses with “100 percent UV” or “UV400” on the label. If there's no UV information on the packaging, don't buy them.
Iwach notes that while many other sunglass features are optional, UV blocking is essential; without it, your sunglasses are just fashion.
2. Choose Your Lens Darkness
Another feature to consider is the darkness of your sunglass lenses. While the darkness of the lens has nothing to do with how much UV protection it provides, it still affects how comfortable you are wearing the glasses.
People with conditions that cause light sensitivity, such as migraine, may be tempted to seek out darker lenses, but regularly wearing very dark lenses can backfire: Dark lenses allow less light into your eye and cause your pupil to dilate, which can actually increase your eye's fatigue and sensitivity to light over time. That's also why you should avoid wearing sunglasses indoors or in dimly lit areas.
The American Academy of Ophthalmology (AAO) recommends using medium-dark lenses for daily use and darker lenses for brighter environments.
If you have persistent light sensitivity, that’s a good reason to see an eye doctor for an evaluation.
3. Choose Your Len Size
The size of your lens is another factor to consider. The bigger the lens size, the more UV rays that are blocked, and the better your eyes are protected from wind, dust, and pollen. Large wraparound glasses offer the most protection from the elements and may be a good option for those with eye irritation from allergies, thyroid eye disease, or other eye conditions.
4. Understand Lens Polarization
Polarized lenses have a chemical coating that reduces glare from the sun and other sources of light. They can also prevent snow blindness as well as the eye strain caused by water or sand reflecting light.
While polarization isn't required, it can be an added benefit, particularly for activities like fishing, boating, skiing, and mountaineering.
However, there are times when wearing polarized lenses is not recommended by the AAO, including when driving at night or reading LCD (liquid crystal display) screens.
When shopping for sunglasses, look for a sticker on the lenses indicating the sunglasses are polarized.
5. Choose Your Lens Color
Sunglass lenses come in many colors, including gray, brown, red, yellow, and orange. While the color can change the style of your sunglasses considerably, Iwach says the color of your lenses is purely a personal preference.
"The actual color of the lens has no bearing on UV protection, polarization, or functionality," says Iwach.
Like lens darkness, you can experiment with different colors and find the option that suits you best.
