Doctor Sparrow, professor of ophthalmology of the subordinate medical centre of Columbia University indicates that most of people shouldn't wear blue sunglasses. Doctor Sparrow is investigating that if it will cause macular degeneration when eyes contact the blue light in the sunlight. This degeneration is the main cause that leads the blindness of the elderly. She thinks that as we grow older, the number of the photosensitive compounds in some retinal cells will increase. While some wavelengths of blue light in spectrum, to the greatest extent, will activate these compounds, promoting the release of harmful free radical, It threatens eyes' health as oxidation process which hurts the retinal cells.
It is sure that blue sunglasses will damage eye heath. On the one hand, blue-ray has a short wavelength, in which the human eye may has the smallest field of view and watch things vaguely; On the other hand, blue is the color closest to UV, which is also detrimental to the optic nerve and easily causing injury to the eye. Clinically, a number of optic nerve diseases have been confirmed with the blue light.
Apart from blue lens, the colored contact lenses with blue stripes which are very popular on the market will also do harm to eyes, so be cautious when choosing them. Then, what color should be secure when purchasing eyeglasses? Doctor Sparrow shows that 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, yellow sunglass can also filter blue light, and then decrease the number of blue light. So it can protect eyes' health effectively. 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.
Finally, the professor reminds consumers that the current sunglasses market is quite sophisticated, and many glasses are poor in quality. When choose glasses, you should choose those with anti-ultraviolet function, the anti-ultraviolet rate is usually between 96% with 98%. 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.