As another summer season approaches, the issue of sunglasses once again resurfaces. Eye care specialists are frequently asked questions whether sunglasses are necessary, and is there really a difference between the cheap ones and the expensive types? The short answer is YES to both questions.
Light, in general and, sunlight in particular is comprised of many units called wavelengths. Each wavelength has a different level of energy ranging from low energy at the red end of the spectrum, to high energy at the blue end. The ubiquitous UV light we hear so much about is situated next to the blue light, and has the highest and most dangerous amount of energy. It is this wavelength of light that we are most concerned with in regard to damage to the eyes.
When this high energy light enters the eye, it is absorbed into the ocular tissues. This energy then acts as a catalyst for an increase in tissue metabolism, and that is when the trouble begins. Individuals with a genetic predisposition toward Macular Degeneration can expect a dramatic increase in the severity of the condition, and a substantially earlier onset of the disease. Systemic disorders such as Diabetes will also put an individual at risk for this disorder. The natural lens in the eye is comprised of Alpha proteins; which are clear. When exposed to UV light, they undergo a chemical change that transforms them into Beta proteins which are yellow. This process is called cataractogenesis and results in cataract formation.
UV light is also absorbed into the outer layers of the eye, and will result in Pinguecula and Pterygiua. These are the yellowish bumps that form near the cornea, on the white part of the eye and the whitish growth on the cornea, respectively. Both are caused by UV exposure. These anomalies are more often found in individuals living close to the equator who are exposed to much higher amounts of UV light then northerners.
Last, but certainly not least is skin cancer. The tissue around the eyes is very thin and highly vascularized (many blood vessels) making it a perfect location for cancer. Both Basal Cell Carcinoma, and Squamous Cell Carcinoma are the result of overexposure to high amounts of UV light.
The best protection for UV light is GOOD quality sunglasses. Good being defined as one that absorbs all the harmful rays of the sun, and covers both the eyes and surrounding areas. While many cheap sunglasses claim to absorb 100% of UV light, the fact is that these do not give the maximum amount of protection that is possible. They do absorb some, but not enough of what will ultimately damage our eyes. Sunglasses bought on the street for $10 will do nothing except increase exposure to UV light. By that I mean; the tint in the lens will dilate the pupil letting in more of the damaging UV light .
The least expensive of the good quality sunglasses are the Ray Bans. They will afford maximum, efficacious protection. At the other end of the cost spectrum is Maui Jim. There are 7 layers of laminates which filter all bad light out, and give perfectly clear vision. All other sunglasses have fewer layers of laminates, but still will give good quality. Other good brands include but are not limited to Oakley, Revo, Vuarnet, Corning, Serengetti, and too many more to list. All prescription sunglasses should include an ophthalmic quality lens and UV coatings. This will make them good sunglasses as well.
When it comes to sunglasses you do get what you pay for. Years of UV light exposure will cause permanent damage to the eyes, and surrounding tissues. It would be most prudent to put aside economics, in favor of competent protection. In the long run, protection is a wise investment.
Dr. Jay B Stockman is a contributing editor for https://www.canadaglasses.com/, and a practicing doctor for New York Vision Associates – https://www.canadaglasses.com/