Patent ID: 8685006

Claim:
A method for preparing control data for a treatment apparatus for surgical correction of defective eyesight in a patient's eye, the apparatus comprising a laser device separating corneal tissue of a cornea by irradiation of pulsed laser radiation, said laser device comprising a contact glass that fixates the cornea focusing the laser radiation through the contact glass on target points, which are arranged in a pattern in the cornea, according to the control data during operation, said method comprising: determining measurement data on parameters of the eye and defective-eyesight data on the eyesight defect to be corrected in the eye, defining a volume on the basis of the measurement data and the defective-eyesight data, said volume being located within the cornea and the removal of the volume from the cornea provided after operation of the treatment apparatus resulting in the desired correction of defective-eyesight, determining a boundary surface which confines the defined volume within the cornea, and determining a three-dimensional pattern of target points in the cornea, wherein the target points are located in the boundary surface and are arranged such that the boundary surface is provided as a cut surface when irradiating the pulsed laser irradiation according to the control data, said cut surface isolating the defined volume in the cornea and, thus, making the defined volume removable, wherein, when determining the boundary surface or the three-dimensional pattern of the target points, deformation of the eye that is due to the contact glass is taken into consideration, such that the determined boundary surface is present after operation of the laser device in the undeformed eye, and generating a control data set which contains the three-dimensional pattern for control of the laser device; wherein the defined volume is defined such that the anterior corneal surface of the eye assumes a radius of curvature R cv * after removal of the volume, said radius satisfying the following equation: R cv *=1/((1 /R cv )+ B BR /(( n c âˆ’1)(1 âˆ’d HS Â·B BR )))+ F, wherein R cv is the radius of curvature of the cornea prior to removal of the volume, n c is the refractive power of the material of the cornea and F is a correction factor; wherein B BR is the refractive power of spectacles suitable for correction of the defective-eyesight and d HS is a distance at which the spectacles having the refractive power B BR should be located anterior of the corneal vertex to achieve the desired correction of defective-eyesight by the spectacles.