There are two types of surgery to treat cataracts: in the past, only the cloudy lens was removed without implanting an IOL. After this old-fashioned surgery, the operated eye would be in a state of high hyperopia and would need to wear a farsighted lens of about 1000 degrees to correct it. In recent years, IOL implantation has emerged worldwide, which restores the eye’s transparency by removing the cloudy lens and implanting an IOL, while leaving the refractive properties of the eye unchanged after surgery and allowing the eye to achieve normal vision without correction.