Age-related cataract is one of the most common blinding eye diseases in the elderly. The main treatment of cataract is phacoemulsification combined with intraocular lens implantation. However, toxic anterior segment syndrome (TASS) is one of severe postoperative complications of the surgery, with main symptoms of aseptic inflammation of the anterior segment, and even severe ocular injury, including corneal edema, decreased corneal endothelial cells, trabecular meshwork damage, and so on. Its pathogenesis is very complex, involving all aspects of the operation, and is closely associated with used surgical instruments, drugs and materials. The disease is easily confused with infected endophthalmitis, and differential diagnosis depends on the typical clinical manifestations and negative results in bacteriological examination of aqueous humor. The prevention of TASS is of great importance, and the treatment is mainly glucocorticoid drugs.