Disclosed herein is a method and a tool for making tunnel incisions of modified architecture in the cornea and sclera. The tool comprises means for making two additional backward incisions made near the side edges of the main tunnel incision. Additional incisions, made to a depth of 10 to 300 μm, are set at an angle of from 15 to 165° relative to the plane of the main tunnel incision. Performing the additional incisions results in a partial downward incision of the tunnel floor (rear part) in its side.