The symptoms of cataracts are different in different periods. Early patients will show photophobia, tearing, myopia deepening and presbyopia reduction. We often see many elderly people wearing a teal glasses on the street, in fact, they really don’t do it because of fashion, but because teal glasses can help them reduce the symptoms of photophobia and tearing and improve the quality of vision. When cataract progresses to the middle stage, patients will experience a certain degree of blurred vision, such as not being able to see the scale of a clock clearly (as shown in Figure 1). As the cataract progresses, the nucleus of the crystal gradually hardens and the patient sees abnormal changes in the color of things, such as a white wall looking yellowish. When the cataract progresses to an advanced stage, the patient’s blurred vision becomes more serious, and he or she cannot see clearly either at a distance or at a close distance, at which point the cataract seriously affects the patient’s life. Figure 1. Cataract performance in different stages