The Electromagnetic Spectrum and you.
All radiation from our sun is measured within what is called the Electromagnetic Spectrum. Gamma rays, x-rays, ultraviolet, or infrared, all these and others are part of the electromagnetic spectrum. All Haber eyewear products provide protection from harmful UV radiation.
Visible light: 380-780 nanometers. The colors we see exist within a very narrow band called the visible light spectrum. Located between 380 and 780 nanometers (1-billionth/meter) this spectrum runs from violet/blue at 380nm to red at 780 nm. Most of the colors you see in nature are combinations of blue, green, yellow or red.
Ultraviolet rays: 100-380 nm. Photochemical in nature. When your skin turns red you are seeing the effects of UV radiation. UV consists of UV A, B, and C. UVC is absorbed in the atmosphere and is of little consequence to humans here on Earth. UVB is absorbed in the cornea and is a major cause of snow blindness or photokerititis caused by long-term exposure to UVB rays. UVA is absorbed in the lens of the eye and is the major cause of cataract formation. Cataracts can be found in elderly migrant workers, lifeguards, surfers and others who spend a great amount of time outside without proper eye protection. Almost all sunglasses today provide protection from all UV A&B rays.
Infrared rays: 780-1400 nm. Thermal in nature. When you feel heat on your skin, you are feeling the effects of thermal radiation. While exposure to infrared may lead to dry, tired eyes, its long term effects on overall eye health is still being debated. Sunglass lens colors and their variations will have differing effects on the attenuation of IR radiation.
Blue light: 380-400nm short wave length radiation on the edge of UV and Visible light, blue has a couple of major drawbacks; one, because of its short wavelength, the lens of the eye is forced to constrict to focus the light on the retina. This in effect causes a distortion in the other colors in a way that is referred to in the optical community as chromatic aberration. Some in the medical community feel that long-term absorption of blue light may be linked to eye afflictions such as macular degeneration. 100% blue light attenuation will increase acuity but a world with out blue is a strange world indeed. Most sunglasses allow for manageable amounts of blue light to transmit allowing proper color recognition while minimizing chromatic aberration.