Patent ID: 7210780

Claim:
Method for determination of a progressive multifocal ophthalmic lens comprising the steps of: choosing a starting lens having a fitting cross marking the primary viewing direction under wearing conditions and a substantially umbilical progression meridian having a power addition greater than or equal to 2 diopters between a far vision reference point and a near vision reference point; defining a current lens equal to the starting lens; optimization, under wearing conditions, of the current lens using as targets: a progression length less than or equal to 25°, the progression length being defined as the angle of lowered viewing from the fitting cross to the point of the meridian at which the wearer's optical power reaches 85% of the addition prescription; and a difference of the mean orientation of the axes of resulting astigmatism to the vertical of less than 2.5° in a first control zone delimited by an ellipse centred on the progression meridian at half height between the fitting cross and the near vision reference point, said ellipse having a major axis greater than 35° and a minor axis comprised between 3.8° and 4.5°.