Apparatus for correcting wavefront aberrations of an eye, the apparatus comprising a laser and a computerized laser control unit for corneal tissue ablation according to an expanded ablation volume, the computerized laser control unit being configured to: determine a wavefront aberration of an eye; determining a corneal ablation tissue volume profile for an eye in three dimensions in order to correct a wavefront aberration after removal of corneal tissue according to said determined profile; determine an expansion factor: (Nc-1) / (Nm-Nc), where Nc and Nm are refractive indices of corneal tissue and a filler material, respectively; determine the volume of expanded ablation in the cornea, where the volume of expanded ablation comprises the profile determined with its thickness multiplied by the expansion factor; where the thickness direction is the direction of a path of light that crosses the cornea; control the laser to perform an ablation in the corneal tissue according to the determined volume of expanded ablation; the apparatus further comprising: a means for filling a stroma space that is left empty by the corneal tissue to which an expanded ablation volume has been ablated with the filler material.Aparato para corregir aberraciones de frente de onda de un ojo, comprendiendo el aparato un láser y una unidad de control de láser computarizada para la ablación de tejido corneal según un volumen de ablación expandido, estando configurada la unidad de control de láser computarizada para: determinar una aberración de frente de onda de un ojo; determinar un perfil del volumen de tejido de ablación corneal para un ojo en tres dimensiones con el fin de corregir una aberración de frente de onda tras la eliminación de tejido corneal según dicho perfil determinado; determinar un factor de expansión: (Nc-1)/(Nm-Nc), donde Nc y Nm son índices de refracción de tejido corneal y un material de relleno, respectivamente; determinar el volumen de ablación expandido en la córnea, d