The sun has given us a lot to think about this summer. The East Coast has seen near-record heat. The state of Maryland has recently promulgated a heat standard for workers. My neighbors in Manchester, N.H., added air conditioning to their entire house after living there for 26 years, and I finally added a room air conditioner to my home, which I have resisted for over 50 years.
According to www.drought.gov, the six New England states joined 31 other states and the U.S. Virgin Islands with the classification “severe (D2) to exceptional (D4) drought for the week of August 10-16, 2022.”
The sun and heat probably encouraged many to think about using sunscreen and sunglasses as well. Good sunscreen lotions offer protection against sunburn and skin cancer and sunglasses offer protection against cataracts.
Lobstermen like Herman Coombs of Harpswell know the importance of protecting their eyes while on the water. MLA photo.
What are cataracts? The first meanings of the word in the dictionary are “waterfall” and “downpour.” In medicine, however, the word cataract is used to describe the lens of the eye when it is opaque, that is, no longer clear. The word comes from the Greek word meaning “to strike down.” When we have cataracts, the function of the eye has been struck down or reduced. What we see will appear hazy, dull or dim; colors will not be bright and details will be fuzzy. This opaqueness or cloudiness occurs when the proteins in the protein-rich lens begin to clump together.
Cataracts result from two basic processes: aging and sun exposure. The changes may be so gradual we don’t notice them for a while.
Clearly, we should take what steps we can early in life to slow down the formation of cataracts in order to preserve our sight. One simple action is to wear sunglasses.
The spectrum of visible light — the light our eyes can see and process — ranges from violet, with a wavelength of 400 nanometers, to red, with a wavelength of 700 nanometers. The shorter violet light waves have the most energy.
The wavelengths of ultraviolet light begin where the visible spectrum left off, at 400 nanometers, and go down to 10 nanometers. There are three types of UV light: UV-A, UV-B, and UV-C. We mostly need to be concerned about UV-A because 100% of those rays reach the earth and our eyes. However, we need to protect our skin and eyes from UV-B as well. Even though 95% of UV-B is absorbed by the earth’s atmosphere before it reaches earth, UV-B wavelengths are responsible for sunburns, skin cancer, and cataracts. The UV-C wavelengths are so short that 100% of UV-C is captured by the earth’s atmosphere.
Why Sunglasses? Sunglasses are designed to filter-out the UV-A and UV-B rays. Look for sunglasses labelled “98% protection for UV-A and UV-B.” The choice of sunglasses should be based on protection first and glamour second. Gray, brown and green sunglasses offer no color distortion. Brown sunglasses absorb blue visible light as well, thus affording protection against another eye condition, macular degeneration. Yellow-tinted lenses block blue light and are best for fog, rain and night driving. These yellow-tinted glasses are also beneficial for computer glasses because they block the blue light from computer screens that can disrupt melatonin production and therefore sleep. If your work requires depth perception, you may find copper, orange or brown lenses helpful.
Studies have found that the inside surface of darkly tinted sunglasses can reflect light into the eyes that comes in from the side. Therefore, the recommendation is to purchase wrap-around glasses, even for light-colored glasses. Other considerations include choosing curved lenses over flat and large over small.
With respect to prescriptions, you can order prescription sunglasses or purchase sunglasses that fit over your prescription glasses. Polarized sunglasses are definitely best for fishermen and those on the water because these glasses reduce glare. You can easily check if your sunglasses are polarized by wearing them while looking at a computer screen. It is fun to see how the image changes when you tip your head!
We have been told that the most important time to be wary of the sun is from 10 a.m. to 2 p.m. when the sun is overhead. Those hours pertain to skin exposure to sun. For eye exposure the critical hours to think about are 8 a.m. to 10 a.m. and 2 p.m. to 4 p.m. when the sun is horizontally in line with the eyes and can sneak in at the sides of the glasses if the glasses are not wrap-around.
When vision becomes too cloudy, cataract surgery is required. This involves substituting an artificial lens for the person’s original lens. Today there are many choices of intraocular lenses that can be inserted, and I learned from my ophthalmologist that these lenses are now treated to filter out UV waves. If your vision becomes cloudy, seek out an ophthalmologist because cataracts left untended can result in blindness. The next time you think about the sun, think also about protecting your eyes by wearing appropriate sunglasses. Eye, eye Captain!
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