Cataract is clouding of the usually transparent lens of the eye or the transparent membrane that surrounds it. It is the leading cause of blindness in the world. Another name used for cataract is gray cataract. This disease can affect all age groups, but it most often affects the elderly population. It can occur bilaterally or affect one eye and can vary from mild to complete clouding of the lens that prevents the flow of light into the eye. Blurred vision makes it difficult or impossible for a person to perform everyday activities such as reading and writing, driving and watching television. When the visual function is damaged, an operation is performed in which the clouded lens is removed and then replaced with a new, healthy lens. Cataract surgery is one of the most successful clinical treatment methods in medicine. Throughout history, it has progressed and corrected all the shortcomings that were present in the past. The operation is quick and painless for the patient, they are discharged home the same day, and the recovery time is minimal, just a few days. In most cases, the operation is performed under local anesthesia by liquefying anesthetic drops in the eye or by injection into the eye area. Local anesthesia is often combined with intravenous sedation, which has the role of relaxing the patient before the procedure. General anesthesia is not excluded, it is only very rare. There are many possible complications after cataract surgery, but their incidence is rare. Some of the more significant ones are postoperative opacification of the posterior capsule, corneal edema, eye inflammation, and cystoid macular edema. Complications such as endophthalmitis and retinal detachment are less common. In this work, the anatomy and physiology of the eye are also described. We described cataracts, how they are formed, what types of cataracts exist and when they occur. Also, at the end, the role of the nurse/technician is described. Nurse has an important role as they are with the patient from the very beginning until discharge home after surgery.