A method for determining by optimization a set of progressive ophthalmic lenses for a given user for whom a near vision power addition (Addn) has been prescribed includes the following steps: measuring the user's near vision individual physiological parameters; determining an ergorama associating, on each lens, a target point in each look direction in worn conditions; determining a target power defect and a resulting target astigmatism for each direction of look under worn conditions, the target power defect and the resulting target astigmatism being determined from the user's measured physiological parameters; computing the power required for each lens for said ergorama by successive iterations to reach the target power defect and the target astigmatism for each look direction.