RCV*(r,φ) = 1 / ( (1/RCV(r,φ) ) + BCOR(r,φ)/ (nc-1 ) ) + F, wherein RCV(r,φ) is the local radius of curvature of the cornea (5) before the volume (18) is removed, nc is the refractive index of the material of the cornea (5), F is a coefficient, and BCOR(r,φ) is the local change in refractive force required for the desired correction of defective vision in a plane lying in the vertex of the cornea (5) , and at least two radii r1 and r2 satisfy the equation BCOR (r=r1,φ) # BCOR (r=r2,φ).
