Clinical performance of polynomial lenses versus tri-curve lenses. I: initial comfort

Twenty-two subjects were asked to wear custom-made polynomial back surface design rigid gas permeable (RGP) lenses and conventional tri-curve RGP lenses to compare the initial comfort provided by the two lens designs monocularly and binocularly. Polynomial lenses, based on tri-curve lens fittings, did not provide better initial comfort than tri-curve lenses. The results seem to indicate that an aspheric back surface alone may not play a very important role in the initial comfort of RGP lens wear. The method used to derive the specifications of the polynomial surface may, however, need further modifications to improve its accuracy.