A lens, system for designing, computer program for designing and a method for designing, with a computer, a progressive addition lens including a distance vision region, a near vision region, and an intermediate vision region, wherein a power gradually changes between the distance vision region and the near vision region, and wherein the progressive addition lens is based on prescription data, the method including: determining a transmission astigmatic performance parameter corresponding to a sum of a prescribed astigmatism included in the prescription data and of a predetermined amount of extra astigmatism; determining lens surface data corresponding to the determined transmission performance parameter.