Intraocular lens providing good vision 23 years after placement.

A Ridley Perspex lens was placed in the posterior chamber of a man''s eye 23 years ago; 20/25 vision has been maintained since. This technique, first carried out in 1949, has been abandoned because of the high incidence of lens dislocation and glaucoma, but many modified versions of the lens have been produced. Implantation of intraocular lenses is still considered experimental, though careful selection of cases and meticulous surgical procedure can yield good results.