It is now an established fact that when an eye is blind solely because of opacities of the cornea sight can be restored to the patient by removing a disk of the opaque cornea and replacing it with a disk of transparent cornea obtained from a human eye. The graft seldom fails to unite, and there is no danger of ophthalmitis or loss of the eye, provided the conjunctival sac has been rendered bacteriologically clean by preliminary treatment. One is therefore justified in operating on a person who formerly would have been considered unsuitable in the hope of restoring some slight vision, as the worst that can happen is that the graft will become opaque, in which case the patient is no worse off than he was before operation. In the majority of cases the surgeon is satisfied if he can restore a small amount of vision, so that the