Everyone enjoys having fun in the sun. We are all aware that excessive sun exposure causes skin damage. But did you know that its ultraviolet (UV) rays can also cause eye damage? Here are some frequently asked questions and answers about UV light and sun for protecting your eyes.
What exactly is UV light?
UV radiation is a type of electromagnetic radiation. Because of its extremely short wavelength, it is invisible to the human eye. The human eye can see only a small portion of the electromagnetic spectrum as light.
Why should I shield my eyes from UV light?
UV light penetrates eye tissues more easily than visible light, potentially increasing the risk of eye problems.
UVA emits the least energy of the three types of UV light but can cause skin aging. Wrinkles and “sunspots” are two of UVA’s most common long-term side effects, but it has also been linked to some skin cancers.
UVB has a slightly higher energy output than UVA. UVB directly damages DNA and is responsible for sunburns and the majority of UV-related cancers.
Although UVC emits more energy than UVA and UVB, it is largely blocked by the Earth’s ozone layer. Apart from the sun, UVC is emitted by welding torches and UV sanitizing bulbs. It penetrates the skin more easily, potentially damaging skin cell DNA and increasing the risk of skin cancer.
How is protecting your eyes from UV rays accomplished?
The simplest and safest way to protect your eyes from UV rays is to wear sunglasses and a hat. Choose sunglasses that fit well and keep light out from around the lenses. Choose a hat with a broad, dark brim to provide shade and reduce glare.
Consider staying indoors during the hottest parts of the day, which are usually between 10 a.m. and 4 p.m. Check the UV index, a measure of UV intensity, in your local weather forecast. Even on overcast days, the UV index can be high.
What are the eye problems associated with UV light exposure?
UV exposure has been linked to a number of eye problems:
- A pinguecula is a protein and fat deposit in the eye’s white part (sclera). It can irritate the eye and, in rare cases, affect how tears cover it.
- A pterygium (Surfer’s Eye) is a growth that extends from the sclera to the clear tissue that covers the iris and pupil, known as the cornea.
- A cataract is a cloudy area in the lens of the eye. Prolonged UV ray exposure modifies lens proteins, resulting in cataract formation and worsening eyesight. Cataracts can cause vision to become blurry, hazy, or less colorful over time.
- UV exposure has been linked to eyelid cancers such as basal cell carcinoma and squamous cell carcinoma. There is no link between UV exposure and other types of ocular cancer.
- The breakdown of the macula — the part of the eye that controls sharp, straight-ahead vision — causes age-related macular degeneration (AMD) to blur central vision. The macula is a part of the back of the eye’s light-sensitive retina. Several studiesThis link will take you away from nei.nih.gov and open in a new browser window or tab. Long-term exposure to UV rays without protection raises the risk of AMD.
How should I go about picking out a pair of sunglasses for protecting my eyes?
UV-blocking lenses are the most important feature of all sunglasses but should not be the only one to be considered when buying a new pair. When selecting sunglasses, keep the following factors in mind:
- The material of the lens. Lenses for sunglasses can be made of a variety of materials, including plastic and polycarbonate. Retailers are required by law to indicate the level of UV protection. Look for lenses with a UV400 rating or that provide 99 to 100 percent UVA and UVB protection. Non-prescription sunglasses are regulated as medical devices by the United States Food and Drug Administration (FDA). It requires manufacturers and retailers to meet minimum standards for UV protection, lens quality, impact resistance, labeling, and other factors. Are you unsure whether your sunglasses have UV-blocking lenses? To test them, many optical shops have a device called a photometer.
- Fit. When it comes to sunglasses frames, comfort should take precedence over style. They should be comfortable to wear, stay in place, and cover the skin around your eyes. A proper fit will reduce light entering the eye from the top, bottom, and sides of the lenses.
- Choose sunglasses based on your activity. UV exposure is increased by activities near water, snow, sand, and other reflective surfaces that reflect light. Polarized lenses are useful for reducing glare caused by snow or water. Wear wraparound sunglasses or goggles to protect yourself from bright light or when doing yardwork or other activities that generate flying debris.
Do contact lenses protect against UV rays?
Some contact lenses are UV-blocking. Wearing UV-blocking sunglasses over your contact lenses protects the skin around your eyes as well as the area of your eyes that contact lenses do not cover.
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Source: National Eye Institute