A recent study published in Archives of Ophthalmology indicates that high-energy visible radiation (HEV), also known as blue light, can be harmful to the human eye. However, many protective lenses don't filter HEV. Are blue light filters really necessary in sunglasses? HEV has the highest energy level in the visible light spectrum, and can be experienced as the intense glares reflecting off of snow and water. Like ultraviolet radiation, overexposure to HEV can lead to macular degeneration of the retina and other problems. When shopping at a wholesale sunglasses distributor or retailer, it's a good idea to ask about all the filters before you buy.

Every moment, the sun emits a vast amount of energy onto the surface of the earth. While some sunlight has proven health benefits, overexposure can be harmful, and a good pair of protective lenses is just as important as sunscreen when it comes to staying healthy. The human eye has some incredibly complex biochemical processes in place to convert the sun's energy into what becomes our vision. When overexposure to UV and HEV damages the eye's ability to heal itself, our eyesight is permanently impacted.

If you spend a lot of time outdoors in the sun, or live at high altitudes or close to the equator, eye protection is even more critical, and people with low blood levels of vitamin C and other antioxidants are more susceptible to eye damage from blue light. Wide open spaces with reflective surfaces - like on a lake or ski slopes - generally have higher UV levels, so take precautions. Common medications like tetracycline, sulfa drugs and birth control can make your skin more sensitive to HEV. The Environmental Protection Agency has developed a UV index that alerts people to the dangers of sun exposure on high-risk days. But while everyone knows about the dangers of UV radiation, there is little open discussion about the detrimental effects of blue light. HEV filters in sunglasses can be just as important as UV protection for the long-term health of your vision.

A good pair of protective lenses can shield you from the more damaging effects of the sun. Quality manufacturers utilize an industry-standard labeling that details the level of UV and HEV protection. Generally, medium to dark lenses that are shaded with a gray, green or copper tint will protect you. Impact-resistant sunglasses made with polycarbonate, or PC-coated sunglasses, also filter out UV rays. In addition to protecting the user's eyes from harmful radiation, many successfully filter out HEV as well.

Almost 50 percent of our lifetime exposure to UV radiation occurs during the childhood years, so a good pair of children's sunglasses for your kids is also highly important. Talk to an eye doctor, or a sunglasses wholesaler or retailer, if you have any questions about blue light and UV filters.