While some people might gaze at a shaft of sunlight and admire its ethereal beauty, Jim Gallas, Ph.D., sees a complex—and potentially dangerous—bundle of spectra and wavelengths. A photo-physicist and physics professor at the University of Texas in San Antonio, Dr. Gallas researches the harmful effects of sunlight on the human eye. His interest in ocular health extends into the commercial realm. Dr. Gallas’company, Photoprotective Technologies, has developed a synthetic form of melanin, a substance found in human skin. When used in sunglasses, it protects the eyes from the sun’s harmful blue light rays, known as High Energy Visible (HEV) light, without affecting wearers’ color recognition. Photoprotective Technologies licenses Several manufacturers that supply melanin lenses to sunglass makers and laboratories.
In 2001, Dr. Gallas and Photoprotective Technologies were honored for their work with melanin sunlenses by Mare Nostrum, an Austrian research group that recognizes scientific advances that benefit mankind.
What prompted you to develop the melanin lens?
I saw the need to create a lens that eliminates UV and reduces HEV light. The idea is to give the eye complete protection from sunlight damage that can lead to macular degeneration as well as cataracts. Once we decided to reduce HEV, it opened up a new lens challenge: the preservation of color perception. So we figured out how to design melanin lenses so they reduce HEV light without disturbing color perception.
How would you characterize the current level of knowledge among eyecare professionals about photoprotection?
Eyecare professionals are well trained in the refraction of light and the use of corrective lenses. But another important aspect in prescribing and dispensing eyewear is the selective filtration or absorption of light. Although there is still disagreement among scientists on the effects of sunlight on the eye, most eyecare professionals recognize the importance of blocking UV radiation. But retinal damage from the blue and violet (the High Energy Visible) part of sunlight is not as well understood. Scientists generally agree that violet and blue light can cause macular degeneration. The precursor to macular degeneration is a photoxidizing process and photoxidation has been shown to be accelerated by blue light. In general, the optical industry has not looked at this. It’s a more serious problem now than ever. We expect to see epidemic proportions of macular degeneration in the next few years.
Who is most vulnerable to HEV light?
Babies and children receive the largest quantity of HEV light. The lenses in our eyes become yellow and brown as we age and filter out a lot of light, particularly the violet and blue. The lens actually takes on a sunglass-like quality. However, from age zero to 18 the lenses in our eyes are crystal clear and let in a relatively large amount of HEV light.
Cataract patients are also at risk. They’re usually around 70 years old. They have their lenses removed, and a new, crystal clear lens is put in its place at an age when their retina is most susceptible to damage from HEV light. This is because the natural antioxidant system in place just behind out retina becomes weakened with age, increasing the threat of photoxidation.
What would be the ultimate photoprotection?
A lens that combines polarization and melanin. Melanin by itself is a really good glare reduction system and polarization by itself it not specifically photoprotective. I’d combine that with A-R coating, too. We believe a light yellow lens with an A-R coating would be ideal for night-time driving.
You have proposed a color perception test that could prescreen a particular sun lens for its effect on a person’s ability to perceive colors. What would it take to implement such a system?
We use the Farnsworth Munsell 100 test (FM100) to see the effects different sunglass lenses have on the ability of an average person to discriminate among colors. A blue-blocking lens will cause a person to behave as though he was colorblind. And many HEV-reducing lenses have a similar effect though not as severe. The point is that different sun lenses can compromise our abilities to discriminate colors to different degrees-some worse than others, and some just not acceptable.
The test, in its current form, takes a long time to administer. I would challenge some enterprising optician or optometrist to create a version of the FM100 test that is more convenient to take-and to use the results like any other eye exam-in this case to ensure good color perception when selecting a new sunlens.