One of the most valuable features available in sunglasses is UV ray protection. Ultraviolet radiation exposure can cause a number of serious eye problems including cataract growth, macular degeneration or retina damage, and even loss of vision. These health hazards stand as a risk for people of all ages, all over the world, year round.
Wearing the proper eyewear while outdoors is one of the simplest ways to prevent such complications. The best sunglasses for UV protection are labeled “100% UV protection”—which includes both UVA and UVB radiation—or are designated “UV400”. While other features like lens darkness, polarization, price or fashion may inspire initial purchasing impulses, ultimately the best sunglasses for your eyes are still those that verified as UV protective.
Knowing this, there is still one more question to consider in the quest for optimal ocular health: do sunglasses lose their UV protection over time?
The results of a 2015 study conducted by scientists at the University of São Paulo in Brazil indicate that the current means of testing provide inaccurate measurements of how quickly sunglasses’ UV protection deteriorates. Their experiments were specific to Brazilian consumer standards but the inconclusive results still speak to broader eyewear industry concerns: there is no definitive evidence that UV protection sunglasses maintain full strength over time and insufficient testing at an international level may leave consumers inadvertently vulnerable to UV exposure.
Noting that even the best UV sunglasses on the market have not been scientifically proven to maintain full protective strength over time, as researchers work to improve testing standards, regular wearers of UV protective sunglasses can best protect themselves in the long term by replacing their eyewear every several years. When shopping for the right style, make sure to consider the fit and temple coverage as well. These elements can contribute additional protection for those regularly exposed to heavy, direct sunlight.