Method for the determination of a progressive ophthalmic lens

A method of making a personalized progressive ophthalmic lens intended to be inserted into a frame chosen by a given wearer having an interpupillary width, and for whom a power addition has been prescribed in near-vision, the method comprising the stages of:

• measuring parameters representing the frame chosen by the wearer, the chosen frame having a bridge with a width measurement;
• choosing an initial lens design having an initial distribution of power and resulting astigmatism defect targets for each direction of viewing under wearing conditions in an ordinary frame;
• defining a working lens to be equal to the initial lens design;
• calculating transformation coefficients using the measured parameters representing the chosen frame and standard parameters;
• calculating a personalized distribution of the power and resulting astigmatism defect targets on the lens by applying the calculated transformation coefficients to the initial distribution;
• defining a personalized progressive ophthalmic lens having the calculated personalized distribution of the power and resulting astigmatism defect targets;
• modifying the initial lens design by calculating the power required on the lens for each direction of viewing by successive iterations in order to obtain the target power defect and the target astigmatism defect of the personalized progressive ophthalmic cut-out lens;
• and producing the personalized progressive ophthalmic lens.