There are several principles for selecting cataract surgery crystals: First, it depends on the patient’s age. If the patient is relatively young, such as young people or middle-aged people, because of the high requirements for the eyes and visual quality after surgery, the IOL should be selected as good as possible, such as aspheric IOL, bifocal, or trifocal IOL, so that the patient can obtain very good visual quality after surgery. However, if you are older, such as 70 or 80 years old or older, and do not have such high requirements for visual quality, you can choose ordinary IOLs. Second, it depends on the condition of the eye. If there is nothing else wrong with the eye except cataract, you can choose a better IOL in this case. However, if the eye is also combined with fundus disease, the recovery of vision after surgery is usually not good, so it is recommended to choose general IOLs. Thirdly, depending on the economic conditions, the price of IOLs ranges from a few hundred dollars to several tens of thousands of dollars, depending on the economic conditions of individuals.