Casting a glass major portion of a multifocal lens blank over a glass segment portion of the blank or impressing the segment into the major portion during or immediately after casting. The glass for the major is selected to coincide in viscosity with the segment glass within a range of 105 to 109 poises at least at one temperature, and that above the crossover point the viscosity of the segment glass is higher than the viscosity of the major glass at the same temperature.