A planning device for generating control data for a treatment apparatus, which by application of a laser device generates at least one cut surface in the cornea, and to a treatment apparatus having such a planning device. The invention further relates to a method for generating control data for a treatment apparatus, which by application of a laser device generates at least one cut surface in the cornea, and to a corresponding method for eye surgery. The planning device is thereby provided with a calculating device that defines the corneal incision surfaces, wherein the calculating device determines the corneal incisions such that after inserting an implant into the cornea, existing refractive errors are counteracted.
