Bad eyes, i.e., the appearance of eye diseases, are caused by many reasons. The common causes are as follows: First, due to genetic factors, such as high myopia, retinitis pigmentosa, optic sensory cell dystrophy, corneal dystrophy, color blindness and other diseases, all related to genetic factors. Second, due to infection factors, such as keratitis, conjunctivitis, dacryocystitis, etc., are usually associated with the eye being infected by pathogenic microorganisms. Third, caused by trauma to the eye, such as penetrating eye injury, traumatic cataract, traumatic glaucoma, etc., where the external stimulus causes damage to the structure of the eye and develops. Fourth, due to autoimmune factors, such as iridocyclitis and uveitis, which are usually more stubborn and cannot be completely removed, and can only be controlled by treatment. Fifth, myopia can be caused by poor eye habits, such as prolonged close eye use and the use of electronic devices.