Dr. Sparrow, the ophthalmic professor at Columbia University Subsidiary Medical Center in America said: ” most people including the old and the young should not 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 believes that as age increased, a number of retinal cells in the photosensitive compounds will be more and more. While in the spectrum, the wavelength of the blue light can stimulate these compounds to the greatest extend and thus facilitate the release of the bad free radicels. It threatens the health of the eye just like damage to retinal cells’ oxidative process.
Blue sunglasses will indeed do damage to the health of eyes. On one hand, blue light has short wavelength, so in the blue light, human eyes has the smallest ken and can not see things clearly. On the other hand, blue is the color closest to UV. Like UV, it is unfavorable to the optic nerve and can easily cause injury to the eyes. Clinically, many optic nerve diseases are proved relating to blue light.
In addition to the blue sunglasses, the popular colorful lenses with blue stripes in the current market are also hazardous to eye health and options should be cautious. So, which color is safe when we are buying sunglasses? Professor Sparrow says that sunglasses of yellow or brown are the best choice. As the yellow light has an intermediate wavelength, the optic cell of human eyes will be most sensitive to it, so that the natural scenery can look clearer. Moreover, the yellow sunglasses can filter blue light, reducing the amount of blue light into the eye, effectively protecting the eye. In addition to yellow or brown lenses, the black lenses are also a good choice as it can reduce the contact with all the colors of light.
Finally, the professor reminds consumers that many mixed sunglasses on the market are not qualified. So, in the choice of sunglasses, people must select those with anti-UV funtion, with its index generally between 96% -98%. Don`t choose to dark color lenses because their transmittancy is low. It will make pupils dilate, which harm eyes.