http://medicalxpress.com/news/2013-10-tooth-implanted-lens.html
The two step procedure was developed in the early 1960s. A tooth, along with a bit of attached bone, is first removed from the patient and machined to accommodate a plastic lens. The lens-tooth is then implanted within a fleshy pouch under the socket of the eye that not being operated on. A flap of skin is also removed from the inside of the cheek, and stitched to the front of the eye which will receive the tooth. The tooth itself is acts a convenient chassis for the lens that is acceptable to the immune system. Provided it is from the patient themself, the tooth should not be rejected.
The second part of the procedure is done about four months later, after there has been sufficient time for vascularization of the tooth. Part of the cornea, iris and the vitreous gel are first removed from the operated eye. Then the tooth and associated bone lamina are cut out and stitched into the prepared eye socket, and re-covered with the flap of cheek skin.