The lens is the regulation of vision, looking at close objects the lens will become convex, the refractive power of light will be enhanced, so as to be able to see objects at close range. The lens can protect the retina, macula, can also filter part of the ultraviolet ray, has a unique light transmission and refraction function, is an important part of the refractive medium of the eye, to the age of 40 years old and above, the lens will gradually appear cloudy, transparency decreases, lens elasticity decreases, there will be presbyopia, cataract and other symptoms. The lens of the eye is a transparent biconvex lens with light transmission and refraction functions, and good vision is due to the fact that parallel rays of light from a distance enter the eye and form a clear image on the retina after refraction through the lens. Daily attention should be paid to the care of the eyes, the key to eye care is to be persistent, every day regularly do eye exercises, eat more eye care food. Don’t use your eyes for a long time continuously. Don’t stay up late: eat less sweets, eat more food rich in vitamin B2, eat more food containing chromium, don’t smoke, drink alcohol.