The sun supports all life on our planet. But the sun's life-giving rays can also pose danger to our health if adequate protection of skin and eyes isn't taken. Solar radiation is a health concern no matter what the season, but summer sun poses significant issues for eye health and vision.
Fun in the sun can translate into potentially unhealthy levels of exposure to the sun's ultraviolet (UV) rays. Pack your vacation suitcase with items to protect your health this summer. The keys to a carefree and healthy vacation include sun block and a hat as well as sunglasses with UV protection from the sun's rays.
The American Optometric Association (AOA) has guidelines for protecting your vision during the summer months and beyond. Dr. Andrea Thau, president-elect of the AOA and Associate Clinical Professor at State University of New York College of Optometry, provides an eye health primer for understanding the dangers posed by summer sun and protecting your eye health and vision as well as that of your child during summer vacation.
Photo Credit: Courtesy of Dr. Andrea Thau
The ABCs of Ultraviolet Rays: UV-A, UV-B, UV-C
Ultraviolet (UV) radiation from the sun comes in three forms. UV-C is absorbed by the ozone layer and doesn't reach the surface of the earth. But UV-A and UV-B reach the earth's surface through the open sky as well as through reflections in our environment. On the summer beach, water, sand and even white concrete buildings reflect UV-A and UV-B rays.
Although UV-B rays are more intense, UV-A rays are 40 to 50 times more prevalent. UV-A rays are the most common kind of sunlight at the Earth's surface, accounting for up to 95 percent of UV radiation. "Protecting the eyes from the negative impact of UV-A and UV-B rays is essential," advises Dr. Thau. "The AOA is working hard to help educate Americans about these dangers so that they can be proactive in protecting their vision and eye health."
Scientists still do not know exactly how much radiation it takes to cause damage to our health. We are unable to tell how much radiation we are absorbing since our bodies do not feel UV rays. The warmth you feel when sunbathing comes from infrared rays that don't cause sunburn and that can be blocked by clouds. Protecting your health from UV damage means understanding UV rays and their health risk factors.
The highest risk of UV exposure that can damage the skin is greatest from 10 a.m. to 2 p.m. But risk for damaging the eyes from UV exposure is greatest from 8 to 10 a.m., and again from 2 to 4 p.m. Explains Dr. Thau, "This is because our brows provide some protection from overhead sun for the eyes during these hours. But you should never take a break from protecting your eyes from summer sun, no matter what the hour."
Unfiltered light can cause damage to the retina, the nerve-rich lining of the eye used for seeing. UV-A and UV-B radiation enter the eyes through the cornea, the transparent layer forming the front of the eye. The cornea functions to bend -- or refract -- light rays as they enter the eye.
Excessive amounts of UV rays over a short period of time, such as sunbathing, can lead to photokeratitis or "sunburn of the eye." Explains Dr. Thau: "Much like sunburn, this is a painful condition that is, fortunately, temporary and rarely causes serious harm. Sufferers will experience red eyes, a sensation of a foreign body in the eyes, excessive tearing and extreme sensitivity to light. It's also important to know that photokeratitis can also be caused by sunlamp use."
Long-term exposure to UV rays increases the likelihood of serious eye problems including cataracts, age-related macular degeneration (AMD) and cancer of the eye and the skin surrounding the eye. The Skin Cancer Foundation reports that cancers found on the eyelid account for 10 percent of all skin cancers.
Savvy Shopping for Sunglasses, Price Does Not Mean Quality
Protect your eyes when outdoors by applying sunscreen around the eyes and wearing both a hat and sunglasses. There are no federal regulations governing UV protection, light transmission levels or the lens quality of sunglasses. The American Optometric Association (AOA) has developed a consumer check list for buying sunglasses, recommending that you go for quality over style. "Remember, price does not equate with quality and protecting your vision," says Dr. Thau. Being a savvy shopper means making sure you get the best protection for your vision first, then finding sunglasses that look good on you; not the other way around. Dr. Thau recommends the following checklist when shopping for sunglasses.
Picture Credit: Courtesy of the American Optometric Association
Your Sunglasses Shopping Checklist
The AOA's 2015 American Eye-Q consumer survey found that nearly half of Americans do not check the UV protection level before purchasing sunglasses. Look for sunglasses that block 99 to 100 percent of UV radiation. Once you find sunglasses that offer UV protection, check the lenses carefully.
- Make sure the lenses are distortion-free by looking through them at a straight line in the distance, such as a door frame. Move the lenses slowly across the line. If the straight line distorts by curving or swaying during this check, the lenses have imperfections.
Several brands of contact lenses also provide UV protection. Since contact lenses rest on the eyes, they are highly effective at blocking UV light from reaching the inside of the eye. However, they do not protect the delicate skin area around the eye. The American Optometric Association recommends the use of UV blocking sunglasses with UV blocking contact lenses for maximum protection.
Protecting Your Child's Vision, A Summer Guide for Fun in the Sun
Children spend considerably more time outdoors than adults, especially during the summer months. As a result, the average American child receives about three times the annual UV dose of their parents. A child's cornea or lens cannot filter out UV rays as effectively as that of an adult eye. This can result in more extensive damage to a child's retina from UV rays.
Children are especially vulnerable to UV damage to their eyes due to their behaviors and lifestyle as well as the structure of children's eyes. Up to 80 percent of lifetime UV exposure occurs before a child reaches the age of 20.
"Hats are no substitute for sunglasses, and baseball caps, in particular, do not offer peripheral protection from UV rays," explains Dr. Thau. Buy comfortable and attractive sunglasses for your children that follow the same guidelines for adults. Dr. Thau adds the following considerations for purchasing children's sunglasses to protect your child's vision and eye health.
- Children's sunglasses are easily available and reasonably priced. Buy a spare pair to replace lost sunglasses so that you know your child's vision will always be protected.
"Wearing sunglasses when outdoors is like wearing a seatbelt in a car," says Dr. Thau. "This is one of the easiest and best steps you can take to ensure your own vision and eye health and foster a lifetime of healthy vision for you and your child."