Depending on the severity of the cataract, there are generally four stages: The first stage, the incipient stage, is the early stage of cataract. The clouding in this stage is usually not very obvious and may appear as striae or radiopaque clouding, which does not affect the naked eye vision too much, so it usually does not need to be treated. In the second stage, immature stage, the clouding of the lens is more severe than in the initial stage. The third stage, the mature stage, after the cataract has reached this stage, the vision will be obviously affected and can even drop below 0.1, and the lens will be found to be milky white cloudy during the examination. The fourth stage, overmaturity stage, refers to the mature cataract that is not treated in time and becomes more cloudy or even appears to liquefy the lens cortex. Therefore, if the disease is allowed to develop at this stage, it may lead to the emergence of secondary glaucoma.