There are many reasons why people need artificial eyes or ocular prosthesis. Thankfully, advancements in science now allow people that have lost an eye to often adapt to their limited vision. A skilled ocularist can now create artificial eyes that so closely match the natural eye, that they typically go unnoticed. The most common cause of eye loss is trauma or injury, but many chronic eye diseases can also lead to eye removal. Five common eye diseases that can ultimately result in the removal of an eye are Painful Blind Eye, Ocular Melanoma, Diabetic Retinopathy, Tumors and Cataracts.

Blindness is defined by the lack of light perception. If a person is completely blind, they suffer from "no light perception" or NLP. Often NLP is accompanied by pain which can be caused by a number of conditions, most commonly the pain associated with the increased eye pressure of glaucoma, a common cause of blindness. In these cases, since there is already no vision in the affected eye, the eye can be removed and replaced with an ocular prosthesis, allowing the sufferer to appear normal and to eliminate the pain.