to separate prescription glasses and sunglasses

Health warning all, have been issued over the past few years, you should have realized that good, despite its vitamin e benefits, the sun in the UVA / UVB ray is not only dangerous, but can prove fatal, when your body within the context of their work caused by all kinds of diseases, the worst is cancer - including skin and eye cancer.
Just as you need to protect your body sunscreen foaming, so you should make sure to protect your eyes and a built-in UVB investment UVA protection of high-quality sunglasses.
Protect your eyes can be traced back to the prehistoric era Inuit wear flat walrus ivory "glasses" blocking the light of the sun, but China in twelfth Century the first documented the lens to the glare of the sun, found. However, it is only in the middle of the eighteenth Century, a person's name, James Ayscough began to experiment with colored lenses of ideas, only the production on a large scale in 1929 by Sam Foster brought the large-scale production of sunglasses beach states.
If you often wear glasses, then you should invest in a pair of prescription sunglasses, then turn your eyes, when you wear is from the inside to the outside. If you don't wear prescription glasses sunglasses as a regular job. In all cases, we must bring sunglasses, as long as you out. If you wear prescription glasses, and hope to have a simple solution, you can consider the photochromic lenses - also known as transitions lenses - lighten and darken, under UV irradiation. This would negate the need to separate prescription glasses and sunglasses.
Experts recommend wearing sunglasses, reflect or filter out 99-100% UVA and UVB ray, wavelength 400 nm. The sunglasses are often labeled as "UV400", only about 95% of the UVA / UVB protection filter, provide more than a standard Sunglasses provide more protection.