Biocompatible, triggerable degradation, polymerizable hydrogels, uses and delivery devices are disclosed. These hydrogels are at least substantially water soluble macromers, having a variety of uses especially for ocular therapy. The macromers include at least one water soluble region, at least one region which is degradable via a triggering event, usually by hydrolysis, and at least two free radical-polymerizable regions. The regions can, in some embodiments, be both water soluble and trigger able degradable. The macromers are polymerized by exposure of the polymerizable regions to free radicals generated by photosensitive chemicals and dyes. An advantage of these polymer hydrogels is that they can be polymerized rapidly in an aqueous surrounding. Precisely conforming, semi-permeable, biodegradable films or membranes can thus be formed on tissue in situ to serve as biodegradable barriers, as carriers for living cells or other biologically active materials, and as surgical adhesives for the eye.
