Method of applying an angular tolerance mark on a lens for correction of astigmatism, and associated lens

摘要

A contact lens has a peripheral tolerance reference marking of two right segments forming an intermediate angle which is dependent on the lens curvature. Independent claims are also included for the following: (i) an astigmatism correction contact lens having a tolerance reference marking formed by the above process; (ii) a set of lenses with tolerance reference markings as described above; and (iii) an astigmatism correction contact lens forming part of the above lens set.