Doc. Sparrow who is the ophthalmologic doctor in Columbia University's branch medical center said most people shouldn't were blue eyeglasses no matter how old you are. Dr. Sparrow is searching that whether the eyes' contact with the blue light of solar rays will cause the age-related macular degeneration. This kind of degeneration eye diseases is the main reason of the blindness of the old. She believes that as age increased, a number of retinal cells in the photosensitive compounds will be more and more. And the wavelength of blue light in the spectrum can activate these compounds to the max, which accelerate the release of harmful free radicals. It threatens eyes' health as oxidation process which hurts the retinal cells.

Blue sunglasses are really harmful to eyes' health. On one hand, the wavelength of blue light rays is very short. The visual range of human eyes is limited, being unable to see clearly; On the other hand, blue, which is close to the color of ultraviolet ray, is harmful to nerves as ultraviolet ray and easy to hurt the eyes. In clinical practices, many optic nerve diseases have been confirmed to be related with the blue light.

Apart from the glasses with blue lens, those colorful glasses with blue stripes which are popular in current market can do harm to eyes' health as well. So, be careful when choosing sunglasses. So, which cheap eyeglasses color is secure to buy? Prof. Sparrow indicated: " either yellow or brown sunglasses are the best choices." Because yellow lights have medium length, which lead the visual cells of human eyes be most sensitive to yellow and make the natural scenery be seen more clearly. Moreover, with the capability of filtering blue light, yellow sunglasses can reduce the amounts of blue light into the eyes and protect effectively the eye health. Except for the yellow and brown lenses, black lens is also a good choice because it can reduce the contact with all the colorful light rays.

At last, Doctor Sparrow advises customers that there are good and bad glassed mixed up, many glasses quality donot pass the test. When choosing reading glasses, you should choose those have the function of antiultraviolet. The UPF is usually from 96 percent to 98 percent. The color should not be too deep, because there would be a serious decline in light transmission in these lens. This makes eye pupil in the dark powder so great that will harm the eyes.