Cataracts have become a common eye disease in the elderly, and the incidence increases with age after the age of 50. at the age of 80, the incidence of cataracts is even as high as 100%. However, cataracts are not easy to detect because of the early faintness, and even when they reach a certain age, their vision decreases and they cannot see anything, they still think it is normal and “it is just presbyopia”. This so-called “presbyopia” view is wrong. Old-age cataracts are not like conjunctivitis with redness, swelling and secretion, nor are they like keratitis with photophobia, pain and obvious loss of vision, but often occur and develop unconsciously. However, during its development, some abnormal visual changes may occur. For example, many elderly people without myopia suffer from temporary myopia, which is due to the increase of lens convexity and change of refractive proximity when cataracts first occur; or flysight, monocular diplopia or polyopia. In addition, if symptoms such as abnormal color vision, dark shadows in front of the eyes, day blindness or night blindness appear, special care should be taken. In the course of cataract development, serious complications can arise if left untreated. Ultrasound emulsification surgery is indicated for most cataract patients. The procedure involves using an emulsification needle with suction through a very small corneal or scleral incision to emulsify and then aspirate the hard nucleus of the lens through a high-frequency vibrating ultrasound head, and then aspirate the cortex cleanly, leaving the capsule intact for implantation of the IOL. The IOL can be implanted in the capsular bag, which is more centrally located and stable. Patients do not have to wait until the cataract is fully mature before having surgery, and can avoid a series of complications during the waiting process.