A photovitrification device, comprising: - at least one photon source, wherein the at least one photon source includes at least one laser source or at least one intense pulsed light source or any combination thereof; wherein the photovitrification device is configured for in vivo corneal photovitrification comprising heating corneal stromal tissue: i) at a heating rate between 5 degrees per second and 20,000 degrees per second, and ii) for a period of time between more than 0.02 seconds and less than 2 seconds, wherein the maximum temperature is between 50 deg. C. and 100 deg. C.; wherein the at least one photon source is configured to generate at least one photon output having at least one wavelength at which a water absorption coefficient at 20°C is in a range between 20 and 300 cm -1 , wherein the photon source average power is 0.25 to 10 W, wherein the photon source is at least one intense pulsed light source and wherein the photovitrification device comprises several components: at least one optical filter, an optical delivery subsystem, a photomask and an ocular fixation device, wherein the ocular fixation device has a thermally conductive optical element in contact with the corneal anterior surface and provides a temperature within ± 5 degrees from a physiological cornea surface temperature T during the photovitrification treatment, wherein the device utilizes a feedback loop mechanism by, continuously or periodically, collecting temperature measurements of at least one of ocular surface temperature, optical element temperature, and room temperature, and based on the obtained measurement adjusting the temperature of the optical element of the ocular fixation device. - at least one photon source, wherein the at least one photon source includes at least one laser source or at least one intense pulsed light source or any combination thereof; wherein the photovitrification device is configured for in vivo corneal photovitrification comprising heating corneal stromal tissue: i) at a heating rate between 5 degrees per second and 20,000 degrees per second, and ii) for a period of time between more than 0.02 seconds and less than 2 seconds, wherein the maximum temperature is between 50 deg. C. and 100 deg. C.; i) at a heating rate between 5 degrees per second and 20,000 degrees per second, and ii) for a period of time between more than 0.02 seconds and less than 2 seconds, wherein the maximum temperature is between 50 deg. C. and 100 deg. C.; wherein the at least one photon source is configured to generate at least one photon output having at least one wavelength at which a water absorption coefficient at 20°C is in a range between 20 and 300 cm -1 , wherein the photon source average power is 0.25 to 10 W, wherein the photon source is at least one intense pulsed light source and wherein the photovitrification device comprises several components: at least one optical filter, an optical delivery subsystem, a photomask and an ocular fixation device, wherein the ocular fixation device has a thermally conductive optical element in contact with the corneal anterior surface and provides a temperature within ± 5 degrees from a physiological cornea surface temperature T during the photovitrification treatment, wherein the device utilizes a feedback loop mechanism by, continuously or periodically, collecting temperature measurements of at least one of ocular surface temperature, optical element temperature, and room temperature, and based on the obtained measurement adjusting the temperature of the optical element of the ocular fixation device. <EOS>