UH, AOA partner to get the word out about summer eye care, protection against UVR

University of HoustonJun 15 2010

As summer approaches, most people step up skin protection from harmful ultraviolet rays, yet aren't as vigilant about their eyes. Optometrists at the University of Houston are involved in a campaign to change this way of thinking.

The University Eye Institute at UH and the American Optometric Association (AOA) are partnering to get the word out about summer eye care and protection against ultraviolet radiation, or UVR, sun exposure. A survey conducted by the AOA found that only 33 percent of Americans said UVR protection was the most important factor when purchasing sunglasses, with 35 percent being unaware of the risks to their eyes.

"During the summer, when more time is spent out in the sun, people start thinking about UVR protection for their skin, but don't take similar steps to safeguard their eyes," said Jan Bergmanson, professor at the UH College of Optometry and founding director of the Texas Eye Research and Technology Center (TERTC). "Lack of awareness surrounding the potential effects of overexposure to UV radiation is concerning, and many people are unaware of the eye health risks to both adults and children associated with spending too much time in the sun without the proper protection."

The TERTC team has measured UVR intensities at the UH campus and found that radiation exceeds what is considered safe levels nine out of 10 days in the summer. Therefore, he says we have every reason to exercise precaution locally here in Houston.

Bergmanson, an international expert in the topic, says some of those risks include both short- and long-term effects on the eyes and vision. These include sunburn of the eyes, most immediately, and developing conditions later in life like cataracts, possibly also macular degeneration, benign growths on the eye's surface, or skin cancer on the eyelids and around the eyes. Symptoms of eye sunburn are blurred vision, irritation, pain, redness, tearing and temporary vision loss (called photokeratitis, or snow blindness).

"Exposure to UVR radiation, which is cumulative over time and puts one at greater risk for developing eye and vision disorders, can be minimized," he said. "UVR protection can be achieved by simple and inexpensive safety measures that can help prevent or limit damage to the eyes."

Tips that may help prevent such damage are to wear protective eyewear any time the eyes are exposed to UVR rays, including cloudy days, as well as taking the extra step to seek out quality sunglasses. The American National Standards Institute has two different standards for UVR protection. A Class 1 UVR-blocking lens absorbs 99 percent of UVB and 95 percent of UVA rays, while a Class 2 lens filters out 95 percent of UVB and 70 percent of UVA rays. Any lens claiming to provide UVR protection must at least meet the Class 2 standard. Therefore, sunglasses that carry a label indicating it provides UV or UVR protection must meet these standards.

It also is important to note that it's not the density of the lens that protects the eyes, as the degree of darkness may have little or no effect on UVR filtering capabilities of a particular lens. Regarding color, Bergmanson says, gray lenses are best because they reduce light intensity without altering the color of objects, providing the most natural color vision. Brown or amber lenses may work better for the visually impaired or athletes, since they increase contrast and also reduce light intensity.

Another consideration is checking to ensure sunglass lenses are perfectly matched in color and free of distortions or imperfections. A simple test for this is if you can see clearly without any curve or distortion when looking through them at a straight edge, such as a floor tile. Cheap lenses, he says, will have optical imperfections that make the lens less useful.

Researchers at TERTC perform research studies in a variety of areas, including environmental effects, such as UVR exposure, on ocular tissues. TERTC research in the field of UVR has been instrumental in understanding the formation of pterygium, a condition that can cause visual disturbance or even blindness. UVR is the only scientifically proven risk factor for developing pterygium. TERTC researchers have demonstrated through their studies that corneal thinning, as can occur in disease and as a result of refractive surgery, leads to an impairment of the corneal UVR filter. This research team also has documented the filtering capability of current soft lenses, and its members authored two prominent position papers on ocular effects of UVR for two separate, highly regarded professional organizations in North American and Europe.

In his work with TERTC at UH, Bergmanson and his colleagues enhance the College of Optometry's contribution to clinical and basic research throughout the United States and abroad, collaborate with industry in research and development of new eye care products and develop new ophthalmic procedures and technologies. TERTC has worked very closely with industry in developing silicone hydrogel lenses that now have more than 50 percent of the soft contact lens market. Studies have included lenses for one-day, two-week and 30-day wearing schedules. Other studies have involved contact lens care solutions and pharmaceutical agents for treating eye disease. TERTC also is engaged in research concerning common and often devastating conditions such as keratoconous and dry eyes.