The capsule of the lens is a transparent, amorphous and cellular membrane. Incubation of the human lens with 6% potassium chloride solution changed the lens capsule into a fibrillar substance, resembling collagen in ultrastructure. The lens produces excessive amounts of collagen fibrils in such pathologic conditions as electric cataract, anterior subcapsular cataract and true and pseudo-exfoliation of the lens capsule.