We have synthesized a range of photolabile conjugates of 3,5-dimethoxybenzoin with acetyl salicylic acid, ibuprofen, and ketoprofen. These conjugates can be precisely kinetically controlled to liberate free drug following exposure to 365 nm light for defined periods. Incorporation of the conjugates into limited-porosity hydrogels, comprising a hydrated copolymer of 2-(hydroxyethyl) methacrylate and methyl methacrylate, crosslinked with ethylene glycol dimethacrylate, leads to dosing devices functional at the molecular level, which release precise doses of drug in response to applied light. A paradigm for the controlled, light-triggered release of "stepped" doses of drugs from polymeric scaffolds is thus demonstrated.