An apparatus for dissecting an eye for the introduction of a photosensitizer into tissue (14, 16) of the eye, the apparatus comprising: - a source of laser radiation, and - a system for guiding and focusing the laser radiation with respect to the tissue (14, 16) of the eye, characterized by: - a computer for controlling said system, the computer being programmed to: control the laser radiation to create in the tissue (14, 16) of the eye at least one insertion channel that extends at least partially into the stroma of the eye, wherein the at least one insertion channel is connected to at least one opening in the surface of the eye and extends substantially in radial direction with respect to a point on an axis of the eye, and control the laser radiation to create in the tissue (14, 16) of the eye two or more side channels associated with the at least one insertion channel, wherein the two or more side channels respectively extend away from the associated at least one insertion channel in a direction different from the radial direction, and wherein an insertion portion for introduction of the insertion channel on the surface of the cornea is cut substantially perpendicular to the surface of the cornea and a sloped part of the insertion channel is cut such that it extends in a sloped manner with respect to the insertion portion, with respect to a horizontal plane through the center of the cornea and with respect to the side channels, which lie deeper in the cornea and extend essentially parallel to the horizontal plane through the center of the cornea. - a source of laser radiation, and - a system for guiding and focusing the laser radiation with respect to the tissue (14, 16) of the eye, - a computer for controlling said system, the computer being programmed to: control the laser radiation to create in the tissue (14, 16) of the eye at least one insertion channel that extends at least partially into the stroma of the eye, wherein the at least one insertion channel is connected to at least one opening in the surface of the eye and extends substantially in radial direction with respect to a point on an axis of the eye, and control the laser radiation to create in the tissue (14, 16) of the eye two or more side channels associated with the at least one insertion channel, wherein the two or more side channels respectively extend away from the associated at least one insertion channel in a direction different from the radial direction, and wherein an insertion portion for introduction of the insertion channel on the surface of the cornea is cut substantially perpendicular to the surface of the cornea and a sloped part of the insertion channel is cut such that it extends in a sloped manner with respect to the insertion portion, with respect to a horizontal plane through the center of the cornea and with respect to the side channels, which lie deeper in the cornea and extend essentially parallel to the horizontal plane through the center of the cornea. control the laser radiation to create in the tissue (14, 16) of the eye at least one insertion channel that extends at least partially into the stroma of the eye, wherein the at least one insertion channel is connected to at least one opening in the surface of the eye and extends substantially in radial direction with respect to a point on an axis of the eye, and control the laser radiation to create in the tissue (14, 16) of the eye two or more side channels associated with the at least one insertion channel, wherein the two or more side channels respectively extend away from the associated at least one insertion channel in a direction different from the radial direction, and wherein an insertion portion for introduction of the insertion channel on the surface of the cornea is cut substantially perpendicular to the surface of the cornea and a sloped part of the insertion channel is cut such that it extends in a sloped manner with respect to the insertion portion, with respect to a horizontal plane through the center of the cornea and with respect to the side channels, which lie deeper in the cornea and extend essentially parallel to the horizontal plane through the center of the cornea.