We see only a very small portion of the sun’s energy. Beyond the Visible Spectrum is where we find some potentially harmful types of “electromagnetic energy. Infrared is felt as heat. Of more concern to us is Ultra-Violet. The earth is protected from most of the dangerous UVby the Ozone layer of our atmosphere, but some of the waves, called UV-A, still get through. In our eyes, UV-A gets absorbed primarily by our crystalline lens, accelerating the development of cataracts.
Sunglasses offer the best defense against the accumulative effect of UV exposure and they should be worn at all times possible while outdoors. This is especially true for children, who will benefit the most over the long term. Eyeglass wearers should get some comfort in knowing that most good quality prescription eyeglass lenses are very effective at blocking UV. Many optical professionals, including Optics Plus, provide only UV protective lenses..