A device for the cross-linking of eye tissue, wherein the device comprises: an instrument designed to introduce a photosensitizer and nanoparticles into the eye tissue, and a first amplification element and a second amplification element, a laser radiation source configured to emit laser radiation for creating a channel in the eye tissue, wherein the laser radiation source also comprising both a Second Harmonic Generation crystal configured to emit a first activation radiation and a Third Harmonic Generation crystal configured to emit a second activation radiation, wherein the first amplification element is configured to amplify the first activation radiation for activating the nanoparticles, and wherein the second amplification element is configured to amplify the second activation radiation for activating the photosensitizer; a system for guiding and focusing the laser radiation, the first activation radiation, and the second activation radiation relative to the eye tissue, and a computer for controlling the system, wherein the computer is programmed to: first, control the laser radiation to create at least one channel which extends at least partially into the eye tissue, second, cause the instrument to introduce the photosensitizer and the nanoparticles into the at least one channel in the eye tissue, and third, simultaneously activate each of the photosensitizer and the nanoparticles, wherein the photosensitizer, when activated, achieves cross-linking in the eye tissue, and wherein the nanoparticles, when activated, catalyze cross-linking by the photosensitizer.. an instrument designed to introduce a photosensitizer and nanoparticles into the eye tissue, and a first amplification element and a second amplification element, a laser radiation source configured to emit laser radiation for creating a channel in the eye tissue, wherein the laser radiation source also comprising both a Second Harmonic Generation crystal configured to emit a first activation radiation and a Third Harmonic Generation crystal configured to emit a second activation radiation, wherein the first amplification element is configured to amplify the first activation radiation for activating the nanoparticles, and wherein the second amplification element is configured to amplify the second activation radiation for activating the photosensitizer; a system for guiding and focusing the laser radiation, the first activation radiation, and the second activation radiation relative to the eye tissue, and a computer for controlling the system, wherein the computer is programmed to: first, control the laser radiation to create at least one channel which extends at least partially into the eye tissue, second, cause the instrument to introduce the photosensitizer and the nanoparticles into the at least one channel in the eye tissue, and third, simultaneously activate each of the photosensitizer and the nanoparticles, wherein the photosensitizer, when activated, achieves cross-linking in the eye tissue, and wherein the nanoparticles, when activated, catalyze cross-linking by the photosensitizer.. first, control the laser radiation to create at least one channel which extends at least partially into the eye tissue, second, cause the instrument to introduce the photosensitizer and the nanoparticles into the at least one channel in the eye tissue, and third, simultaneously activate each of the photosensitizer and the nanoparticles, wherein the photosensitizer, when activated, achieves cross-linking in the eye tissue, and wherein the nanoparticles, when activated, catalyze cross-linking by the photosensitizer..