Sunglasses do a lot of things. They always make a fashion statement (good or bad). They significantly cut glare. They hide your eyes as you check out your fellow patio diners. They protect the eyes during outside sports. However, good sunglasses have benefits that are more than cosmetic or convenient.
The most important function of sunglasses is to block UV light. This type of light is not visible to the human eye and comes in three forms: UVA, UVB, and UVC. UVC is the most damaging form, but all that is emitted from the sun is filtered by the atmosphere. It’s main application is in industrial sterilization processes. UVA from the sun does reach the Earth’s surface, but it’s effects are generally limited to accelerating aging. A black light emits UVA. UVB from the sun reaches the Earth’s surface in great amounts. It can cause cancer, free radical damage, and disruptions in one’s DNA.
Sun damage to the eye can occur in a variety of areas. A very common location for basal cell carcinoma and squamous cell carcinoma is the eyelid. In fact, the bony ridge above the eye and the eyebrow help to minimize UV exposure to this area of sensitive skin. However, they cannot protect it completely. Being outside on the beach or ski slope with no eye protection frequently leads to photokeratitis, a painful inflamed cornea, due to the intense amounts of sunlight and glare. By far the most prevalent eye effect of the sun is cataracts. Cataracts are an opacity or yellowing of the lens that largely occurs due to accumulated UV damage. The reason they typically occur later in life is that while we are younger, we simply haven’t had enough lifetime UV exposure. Getting in the habit of wearing sunglasses faithfully helps to delay the development and severity of cataracts. Finally, a less common but very severe sun/eye complication is called solar retinopathy. This is effectively a sunburn in the back part of the eye that can lead to temporary or permanent vision loss.
Sunglasses are of little value if they do not block 100% of UVA and UVB radiation. The ophthalmic quality sun lenses that we use at Park Slope Eye always block these wavelengths. Additionally, our optometric stylist and doctors will ensure that they fit your face properly to offer the maximum amount of protection. If you don’t wear contacts, we can even add your prescription to them. Lower quality department store or drug store shades may or may not block all UV light, and they cannot receive prescription lenses. The manufacturers of knockoff sunglasses typically thumb their nose at copyright law and frequently put the same little value on UV protection. They are the one type of sunglasses that you are best to avoid in all cases. Getting in the habit of regularly wearing your shades when you go outside will help keep your eyes healthy throughout your life. Wearing the right kind of shades may even get you a few second glaces from the other folks on the sidewalk.