The lens is one of the refractive interstitial elements of the eye, refracting and transmitting light from the outside world into the eye, and is a necessary pathway for external light to enter the eye. If the transparency, position and shape of the lens change, it will cause vision loss; the lens has a regulating effect, when looking at close objects, the lens will become convex, the refractive power of light will be enhanced, so that you can see objects at close range. As we age, the elasticity of the lens gradually decreases, and the regulating effect gradually weakens, causing the phenomenon of “blurred vision”. In addition, the lens can filter out some of the ultraviolet light, which has a certain protective effect on the retina.