The present invention relates to altering the physical and/or chemical properties of at least part of at least one tissue in the eye. In a specific embodiment, it relates to the treatment and/or prevention of myopia. An activating energy source is utilized to photopolymerize or crosslink molecules in the sclera, thereby increasing the strength of the tissue. The individual is administered a crosslinking reagent or photopolymerizable molecule that becomes associated with the membrane, which is then precisely exposed to an energy source, such as light or ultrasound.