Cataracts are degenerative changes causing a decline in optical quality, which are due to the decreased transparency or color change of a structure in the eye called the lens. The pathogenesis of cataracts is quite complex, resulting from the long-term combined effects of various internal and external factors on the lens. The lens is situated in the fluid environment of the eye, and any factor impacting this environment, such as aging, genetics, metabolic abnormalities, trauma, radiation, poisoning, localized nutritional disorders, as well as certain systemic metabolic or immune diseases, can directly or indirectly damage the tissue structure of the lens, interfere with its normal metabolism, and cause the lens to become opaque.