Systems and methods for applying and monitoring eye therapy

A system for activating a cross-linking agent applied to a cornea of an eye, comprising:

• a light source including a light emitting diode for emitting a non-ablative photoactivating light, the light source emitting linearly polarized light or a beam of light capable of being filtered to pass linearly polarized light, wherein the light source is configured to be applied with a power of between 30 mW and 1 W and deliver the photoactivating light so that a dose between 5 J/cm2 and 30 J/cm2 can be absorbed by the cornea;
• a digital micromirror device (DMD) including a plurality of mirrors arranged in a matrix, the plurality of mirrors configured to selectively reflect the photoactivating light from the light source to provide a pixelated illumination to be directed to a cornea of an eye, the pixelated illumination including pixels defined by the mirrors in the DMD;
• one or more optical elements positioned to direct the pixelated illumination from the DMD to the cornea;
• a controller configured to control the DMD to programmatically select which of the mirrors reflect the photoactivating light to provide the pixelated illumination to a selected region of the cornea, wherein, at one particular instant in time, the pixelated illumination is defined by a two-dimensional array of the pixels, the controller being configured to control the light source to determine a duration for the pixelated illumination to generate cross-linking activity in the selected region of the cornea;
• and
• a feedback system configured to provide the controller with feedback information for controlling the DMD, the feedback system including an eye-tracking system having a video camera,
• wherein the feedback system is further configured to measure changes in biomechanical strength or stiffness in response to a corneal deflection, and
• wherein the controller is further configured to determine an amount of cross-linking based on the feedback information, and controlling the light source comprises modulating the DMD spatially and temporally at least partially based on the determination.