There are three basic designs of scleral contact lenses. The identity of the design lies in the size and the amounts of lens for corneal coverage and primary contact to the eye or where the bearing of the lens lies in the landing zone. The three different types are corneo-scleral lenses, that do not contain a tear reservoir and land on the cornea. Number two, the corneo-scleral and semi-scleral, land on both the cornea and sclera parts of the eyes. And number three, full and mini scleral lenses also known as haptic lenses land only on the sclera.