With summer and long, sunny days upon us, we will be spending more time outdoors. Whether you’re in the park, on the beach or just taking a stroll, it’s important to protect your eyes from the sun’s harmful rays. Sunglasses can prevent damage to the eyes from the sun that could be permanent, keeping certain wavelengths of light from entering the eye. Among their many attributes, they can reduce the amount of light reaching the eye, protect against harmful UV light, decrease glare and increase contrast.
For this reason, we urge everyone to wear sunglasses, also called absorptive lenses, whenever you are outdoors – and particularly during long hours spent in the intense summer sun. Even on a cloudy day, however, UV rays are present and it’s best to wear sunglasses. It’s also important to wear a hat with a wide brim or a visor to shield your eyes from the sun’s rays. Wearing a hat and sunglasses decrease UV exposure by 30 percent.
This is especially important for people with impaired vision. If you have a condition such as glaucoma, diabetic eye disease or retinitis pigmentosa, reducing glare and/or maximizing contrast are key to seeing your best every day.
People who spend excessive hours in the summer sun have an increased risk in later life of developing age-related eye conditions, such as macular degeneration. Moreover, prolonged exposure to UV light can lead to other eye conditions, including cataracts and corneal problems. According to the National Eye Institute, an estimated 20 percent of cases of cataract are caused by extended UV exposure.
Sunglasses should absorb 99-100 percent of UV-A and UV-B rays and provide 400 UV protection. The lenses that may work best for you depend largely on your routine and daily activities, or your “visual function,” rather than your eye condition. Protecting your eyes from sun exposure is particularly important for those involved in outdoor sports and for infants.
When selecting sunglasses, here are some pointers to keep in mind to safeguard your vision:
- A dark lens does not necessarily have UV protection. The key characteristic to look for is an indication that the lenses absorb 99 to 100 percent of UV light, particularly UB-B. An ultraviolet-blocking coating can also be placed on any lens, regardless of the degree of tint. However, a coating does not block as much UV light as the protective lens.
- When purchasing sunglasses, look for those made by well-known optical manufacturers and labeled to block against UVA and UVB.
- The best protection comes from polycarbonate lenses, which are impact resistant (so the lenses will not shatter and damage the eyes) and block both UVA and UVB rays. Only a vision care professional can provide polycarbonate lenses.
- When playing sports, wear safety sports glasses with polycarbonate lenses to guard against UVA and UVB as well as protecting the eyes against balls, bats and other potential hazards.
- Whether or not you have vision problems, you may have difficulty adapting to abrupt changes in light levels, such as when you enter a movie theater. Wearing sunglasses outdoors will help to decrease the adjustment time indoors. For those with vision impairment, without the use of sunglasses, it may take from five to 30 minutes to adjust to lighting changes.
- If you have a vision impairment, speak with your eye care professional or low vision specialist (optometrist or ophthalmologist) to learn which sunglasses best suit your needs. Absorptive lenses (sunglasses) come in a wide range of tints, with varying degrees of light transmission.
Types of absorptive lenses include:
- Wraparounds: These plastic lenses fit over prescription glasses. Close-fitting, wraparound style glasses are best. They come in a wide selection of colors and transmissions and have built-in side shields and a top rim to prevent light from entering the eyes. Most of these provide sufficient UV protection, but always check to be sure. Glasses that are loose and/or do not wrap around the head still allow rays in from the open sides of the glasses.
- Photochromic/transition lenses: These lenses get darker when exposed to sunlight and can incorporate eyeglass prescriptions. Standard versions are available in plastic and glass. Specialized photochromic lenses that can cut light out below certain wavelengths may be prescribed for patients with low vision. These come in specific colors and are only available in glass.
- Polarized lenses: These lenses prevent the transmission of light that is reflected from a smooth surface and causes glare. They can be beneficial when outdoors near or on the water, in the snow or while driving. Some wraparounds are polarized.
- Tints: Tinted lenses come in a variety of colors and light transmissions. While they can be helpful, they may not work for everyone. Wraparounds and specialized photochromics can provide unique solutions beyond just tinting a pair of glasses.
What Can I Do Next to Take Care of My Eyes?
Lighthouse Guild’s full service Optometric and Low Vision Clinic is dedicated to diagnosing and treating eye disease. The clinic also provides comprehensive low vision services to children and adults with visual impairment.