Method for optimising a progressive ophthalmic lens and method for producing same

A method for optimising a progressive ophthalmic lens and to a method for producing same. Further disclosed it a method for optimising a progressive ophthalmic lens the distribution of power and undesired astigmatism along an optical surface is optimised by minimising the function:F⁢⁢·=·⁢⁢∑i=1n⁢⁢w⁢⁢1i⁢(Asti)2+w⁢⁢2i⁢(Powi-TargetPow)2wherein w1i and w2i are 0 or positive, and wherein the subscript i indicates the different points of the optical surface. Summation additionally comprises a term from the group formed byw⁢⁢4⁢mi·(∂Asti∂x)m,w⁢⁢5⁢mi·(∂Asti∂y)m,w⁢⁢6⁢mi·(∂Powi∂x)m,w⁢⁢7⁢mi·(∂Powi∂y)mand multiplications thereof,m being greater than or equal to 1,and w4mi, w5mi, w6mi and w7mi being greater than or equal to 0,wherein if any of the terms of the group formed by(∂Asti∂x)m,(∂Asti∂y)m,(∂Powi∂x)m,(∂Powi∂y)mand multiplications thereof is less than 0, then same is substituted by the absolute value thereof, and wherein, if m=2 and w42i=w52i, neither being 0, then summation additionally includes at least one other term from the group.