Medical studies have increasingly tied chronic exposure to UV and near-UV rays to ocular diseases like cataracts and macular degeneration. Shade does not provide adequate protection, as the eyes still absorb UV radiation, especially when near water, snow, or highly reflective surfaces like concrete or sand. The best way to protect your eyes is a quality pair of sunglasses that meet recommended criteria for sun protection.
Although lenses are the most important feature, if the frames allow a considerable amount of light to enter the eyes without first being filtered through the lenses, much of the sun protection is lost. The most effective frames are a wrap-around style that blocks light from entering at the sides. Wraparounds also hug the face, lessening the amount of light that can enter over the top or at the cheekbones.
It is also vital that the lenses offer maximum sun protection. This isn’t dependent on how dark the lenses are, but rather on their ability to filter out certain wavelengths. Look for lenses that block 100% UV-A and UV-B rays. These are the same rays that cause sunburn and skin cancer. Though UV-C rays are often mentioned, the earth’s atmosphere blocks virtually all of these.
It is also important to look for lenses that filter near-UV light. Studies suggest that excessive exposure to near-UV light contributes to macular degeneration as we age, a chronic disease that results in deteriorated visual clarity. Near-UV is also called high energy visible (HEV) light or “blue light.” These rays are less destructive than UV-A or UV-B rays and do not have to be blocked entirely, but this spectrum should be at least partially filtered to provide better sun protection.
The near-UV range falls between 400 and 515 nanometers (nm) within the visible light spectrum. If glasses “block near-UV to 400nm,” this is an indicator that they don’t block much of this spectrum. Conversely, if they “block near-UV light to 515nm,” they filter out the entire spectrum, eliminating blue.
Yellow lenses remove the blue light spectrum completely, filtering all near-UV rays. This distorts color perception and feels harsh to many people. Amber lenses block some of this range and are less harsh then yellow lenses, preserving more true color. Melanin lenses are fairly new, based on the body’s own form of built-in sun protection, and filter a large portion of the near-UV or blue light spectrum while maintaining the truest color of HEV-blocking lenses.
Quality sunglasses will have a tag or accompanying information revealing the amount of sun protection they provide. Sunglasses missing this information probably don’t provide maximum sun protection, as 100% UV blockage and HEV filtering are valuable selling points.
Though sunglasses don’t have to be expensive, quality sunglasses are an investment in the long-term health of your eyes. Sunglasses that provide good sun protection will also help to protect the delicate skin surrounding the eyes from premature wrinkles and skin cancer. All the way around, a good pair of sunglasses is an investment well worth the money. Your eyes deserve good sun protection.