Recent Developments in the Manufacture, Fitting and Prescription of Contact Lenses of Regular Shape

Even so the necessary range of fittings to accommodate the varying corneal diameter was not provided. It was against this background that Dallos introduced his glass, moulded contact lenses in 1933. These lenses have a scleral segment of irregular contour corresponding precisely to the patient's sclera. This correspondence was at first secured by making the lens to a mould from each eye but latterly has been obtained by adapting by hand a ready-made lens of approximatelv the correct (shape. At one sweep most of the difficulties were removed and a practical contact lens, adaptable to almost any patient that could possibly wear one, became available. The success of the method was so great that the increased cost, the tedious and prolonged fittings bv a technician and the troublesome taking of a mould from each eve were accepted and, for the time being, further consideration of the improvements possible alonlg the lines initiated by Zeiss was abandoned.