title: Variable focus spectacles.
abstract: The history of prostheses for presbyopia is reviewed with an account of the development of variable focus spectacles. They have fluid-filled cells, with one flexible wall on the back of the base lens. The curvature of the flexible wall can be varied by operating a bellows in one side-arm. Their use for presbyopia, aphakia, and glaucoma is considered. The spectacles are believed to have reached a stage where they are ready for commercial production.
mesh_terms: D005139:Eyeglasses; D006801:Humans; D011305:Presbyopia / Q000628:therapy; D011474:Prosthesis Design