The manifestation of cataract under slit lamp is different depending on the stage. If it is an incipient cataract, under the slit lamp you can see vacuoles or aqueous gaps forming in the cortex of the lens, usually with the aqueous gaps expanding from the periphery to the center, and you can see very obvious streaks or radial clouding in the vitreous. If the cataract is in the distended stage, a uniform gray-white clouding of the lens can be seen at this time. In mature cataracts, the entire lens is completely cloudy and milky white under the slit lamp, and in some patients, calcified spots can be seen on the capsule. Therefore, cataracts in different stages behave differently under the slit lamp. It is recommended that when vision loss is considered to be caused by cataract causes, early examination at the hospital is needed and early surgical treatment is required when indications for surgery are available.