A device for generating control data for controlling a laser for surgical correction of defective vision of an eye of a patient, wherein - the control data are adapted to control a laser which cuts corneal tissue by irradiating laser radiation into the cornea of the eye, and - the device generates the control data such that the laser, during operation according to the control data, emits the laser radiation such that a volume in the cornea is isolated, the removal of which volume from the cornea effects the desired correction of defective vision, - wherein to determine the control data, the device -- either calculates a radius of curvature Rcv * which radius the cornea has without the volume and which radius is locally varying and satisfies the following equation: R C V*(r,φ) = 1 / ( (1/R CV (r,φ)) + B COR (r,φ)/ (n c -1)) + F, wherein R CV (r,φ) is the local radius of curvature of the cornea before the volume is removed, n c is the refractive index of the material of the cornea, F is a coefficient, and B COR (r,φ) is the local change in optical refraction power in a plane lying in the vertex of the cornea and required for the desired correction of defective vision, -- or calculates an optical refraction power B* CV which optical refraction power the cornea has without the volume and which radius is locally varying and satisfies the following equation: B * CV r φ = 1 1 B CV r φ + B COR r φ + F n C − 1 wherein B CV (r,φ) is the local optical refraction power of the cornea before the volume is removed, and - seen in polar coordinates, there are at least two radii, r1 and r2 for all angles φ, for which B COR (r=r1,φ) ≠B COR (r=r2,φ) holds true, characterized in that when determining the control data, the device defines the local change in optical refraction power B COR (r,φ) such that there is a characteristic radius r ch for which radius thus B COR (r<r ch,φ=const) = B a ≠ B b = B COR (r>r ch,φ=const) holds true. - the control data are adapted to control a laser which cuts corneal tissue by irradiating laser radiation into the cornea of the eye, and - the device generates the control data such that the laser, during operation according to the control data, emits the laser radiation such that a volume in the cornea is isolated, the removal of which volume from the cornea effects the desired correction of defective vision, - wherein to determine the control data, the device -- either calculates a radius of curvature Rcv * which radius the cornea has without the volume and which radius is locally varying and satisfies the following equation: R C V*(r,φ) = 1 / ( (1/R CV (r,φ)) + B COR (r,φ)/ (n c -1)) + F, wherein R CV (r,φ) is the local radius of curvature of the cornea before the volume is removed, n c is the refractive index of the material of the cornea, F is a coefficient, and B COR (r,φ) is the local change in optical refraction power in a plane lying in the vertex of the cornea and required for the desired correction of defective vision, -- or calculates an optical refraction power B* CV which optical refraction power the cornea has without the volume and which radius is locally varying and satisfies the following equation: B * CV r φ = 1 1 B CV r φ + B COR r φ + F n C − 1 wherein B CV (r,φ) is the local optical refraction power of the cornea before the volume is removed, and -- either calculates a radius of curvature Rcv * which radius the cornea has without the volume and which radius is locally varying and satisfies the following equation: R C V*(r,φ) = 1 / ( (1/R CV (r,φ)) + B COR (r,φ)/ (n c -1)) + F, wherein R CV (r,φ) is the local radius of curvature of the cornea before the volume is removed, n c is the refractive index of the material of the cornea, F is a coefficient, and B COR (r,φ) is the local change in optical refraction power in a plane lying in the vertex of the cornea and required for the desired correction of defective vision, -- or calculates an optical refraction power B* CV which optical refraction power the cornea has without the volume and which radius is locally varying and satisfies the following equation: B * CV r φ = 1 1 B CV r φ + B COR r φ + F n C − 1 wherein B CV (r,φ) is the local optical refraction power of the cornea before the volume is removed, and - seen in polar coordinates, there are at least two radii, r1 and r2 for all angles φ, for which B COR (r=r1,φ) ≠B COR (r=r2,φ) holds true,