The lens of the eye is the lens of the eye, located between the iris and the vitreous humor, biconvex transparent tissue, elastic, similar in shape and role to a convex lens, can reflect the image of objects near and far, clearly on the retina, is the only refractive interstitial with the ability to regulate the eye. The lens has a refractive effect on light, and its main role is to adjust the refractive power so that the focus of the eye can fall accurately on the retina when looking far or near, so that objects can be seen clearly; at the same time, the lens can filter some of the ultraviolet light, which has a protective effect on the retina. However, as we age, the nucleus of the lens gradually concentrates, expands, and loses elasticity, and the eye’s ability to adjust becomes poor, resulting in presbyopia, which is effectively treated with presbyopic lenses. The lens keeps aging and gradually becomes cloudy, which may eventually form cataracts. The only effective treatment for cataracts is surgery to replace the lens with an IOL, allowing cataract patients to regain clear vision. It is important to protect the eyes in daily life, such as paying attention to eye hygiene, not using the eyes excessively, and allowing the eyes to get sufficient rest to slow down the aging rate of the lens as much as possible.