commonly used laser for alignment purposes the hene laser beam may be placed on the path of the fsec beam by a special mirror 245 which is transparent for ultrashort laser beams where the ultrashort beam preferably operates at a wavelength the vicinity of u03bb 800 nm the hene beam may be split by a beam splitter 210 into two beams each of them following the same path as the ultrashort laser beams however because they have a different wavelength the hene beams are not tightly focused by focusing optical lenses 195 into the patient 39 s eye the crossing of hene laser beams in the eye may illuminate the lens material the image may be magnified by an optical microscope and may be shown on a monitor providing a fast and simple method of choosing cataractous tissue to be multi photon ablated by the ultrashort laser beams the focusing optical lens 195 may be moved in the perpendicular horizontal x axis and parallel z axis direction as well as vertical y axis relative to the plane of the beams using a three stage remotely controlled high precision position control system or micro scanner each scanner may operate one lens and may be computer controlled the operator may choose the position of the crossing point by observing the microscope images on the monitor and may give instructions to the control system via the computer interface as illustrated in fig2 the depth of focus of the microscope may for instance be controlled either by the computer or manually by an operator a ccd camera.