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 of any eye disorder, although in particular embodiments the individual has a thickened Bruch's membrane. An activating energy source is utilized to effect a controlled diffusion enhancement and/or degradation of Bruch's membrane that enables improved diffusional transport between the choroid and retina. The individual is administered an inactivated diffusion-enhancing molecule that becomes associated with the membrane, which is then precisely exposed to an activating energy source, such as light or ultrasound.