Contact lens with flexible central portion

Claim 1

A soft plastic corneal contact lens adapted to float on and adhere to the cornea comprising a transparent, noncontacting, resiliently distortable and normally dome-shaped central lens portion adapted to form with the cornea the upper wall of a tear fluid chamber, an outer peripheral portion having spaced projections formed on the inner surface, said projections each having an inner concave surface to engage with the corresponding area of the convex-shaped peripheral portion of the cornea, said spaced projections providing radial fluid passages therebetween for egress and ingress of tear fluid from and into the fluid chamber, and an intermediate thickened portion joining the central and peripheral portions, said spaced projections being substantially kidney shaped in outline and each increasing in thickness from the outer to the inner periphery of said peripheral portion, the inner and outer edges of said kidneyshaped projections being spaced from the intermediate thickened portion and the peripheral edge of the lens, respectively, said central lens portion being adapted to serve as a diaphragm wherein on eyelid closure the diaphragm yields inwardly without engaging the cornea forcing tear fluid out of the chamber, and wherein on eyelid opening the diaphragm springs back to normally domed position and thereby drawing tear fluid into the said chamber.