A scleral contact lens is a gas permeable contact lens that is unique in that it doesn't directly touch the front of the eye (the cornea). Instead, it vaults over the cornea and sits on the scleral (or white of the eye). While that might sound unusual, these lenses offer the maximum benefit of protection and lubrication for those suffering from poor vision or dry eye complications.
What type of person would benefit from scleral contact lenses?
People with distorted eyes: Keratoconus, complications after LASIK, after corneal transplantation, etc.
People with severe dry eyes: Sjogrens, Rheumatoid Arthritis, Graft-versus-host disease, graves disease.
People who can't close their eyes all the way: Nerve Palsys, Bells Palsy, Acoustic neuroma, after eyelid surgery.
People who have very high prescription: "normal" eyes with high vision correction can benefit from this lens because of it's great vision it provides.