BoomerGirl Diary

Summer is fast approaching and as the spring rains abate, we find ourselves reaching for our sunglasses. So what should the “fashionista” look for in sunglass purchases this year? Luckily, fashion and health dovetail nicely with this year’s trends.

Size: The bigger, the better! Larger frames are the newest look and also provide more coverage of not only our eyes but also the tender skin that surrounds our eyes. That means the more protection from the harmful rays of the sun, the less aging changes to our eyelids and a lower risk of skin cancer which has a tendency to occur on the lid margins.

Lenses: Put on your thinking caps and follow closely for a little optical physics journey! The rays of the sun range from red (long wavelengths) to blue (short wavelengths) and ultraviolet (REALLY short wavelengths). We know light exposure can cause pterygia, small benign growths on the ocular surface of the eye. Epidemiological research suggests that Age Related Macular Degeneration (AMD) is directly related to the damage of blue cones in the macula caused by prolonged exposure to bright visible light.

Researchers are currently looking at the connection of light exposure and the development of cataracts. We know it is very important to protect our eyes from the ultraviolet rays, which are about 400 nanometers or less in wavelength. But now, the hot topic is whether or not we should also be blocking the visible or bright blue wavelengths. These rays are 446-477 nm. in length, and when our eyes are exposed to these little gals, they send a message to our brain telling us it is light outside and time to work and play. In other words, this exposure is what stimulates the production of melatonin, a hormone that keeps us happy with normal sleeping rhythms. Theoretically, if we constantly block our exposure to the visible blue light with blue-blocking sunglasses or filtering intraocular lens implants used in cataract surgery, we decrease the amount of this important hormone. The National Institute of Health is currently studying this issue. Whew. So, for our purposes based on the best information that is available, here are my recommendations.

1. Sunglasses should be labeled, if purchased over the counter, with assurance that 98-100 percent UVA and UVB protection is present. Many inexpensive lenses carry this protection. Do not assume the protection is there without the label. The current FDA guidelines are for 60 percent UVA and 70 percent UVB and it is only voluntary that a manufacturer lists their filter quantity.

2. The amount of UV protection is completely independent of the amount of tint in the lenses. Even a clear lens can have 100 percent UV filter. The amount of tint chosen is personal preference.

3. Polarized lenses are great for filtering glare especially in activities that include reflected light such as fishing, boating and driving with light reflected off the water, road and car surfaces. They however, do not provide us with any additional protection from the sun so confirm that those lenses also have the UV filter. Also, beware that polarized lenses may filter images on LCD screens making the gas pump screens impossible to read!

4. Blue-blocking lenses were first used for patients with retinitis pigmentosa and now CPF (Corning Photochromic Filter) lenses are suggested for macular degeneration and cataracts. The blue-blocking lenses have actually been shown not to improve visual acuity, but some patients claim to be more comfortable with them. Others do not like the loss of color discrimination. These lenses are usually a yellow or amber in appearance and therefore may change the appearance of blue and green objects. The jury is still out as to their role in the prevention of AMD.

Lastly, keep in mind that although the incidence of macular degeneration increases 50 percent from the ages of 50-75, it is the lifetime of UV exposure that increases our risks. The largest light exposure in our lifetime is between the ages of 0-20, so remember to put some shades on the kids too! Sunglasses are a comfortable way to have fun in the sun while protecting our eyes so when you head out the door make sure you look like a movie star with a pair of cool shades that you'll want to wear!