Corneal tattooing is not only possible, but it has been known and done now for over 2,000 years — it became almost commonplace in the late 19th century and into the 20th century to correct defects such as corneal scarring and leucomas. These days, it is done less often because contact lenses are very effective at covering these defects, and prosthetic technology is also more accessible. However, not everyone can wear contact lenses, and not everyone wants their eyeball popped out even if it is blind; hence cosmetic tattooing of the eye.