Polymer vesicles (polymersomes) are a synthetic analogue of liposomes. Block copolymers that mimic the lipid amphiphilicity can self-assemble into nano/micro sized polymer vesicles. Physicochemical properties of polymer vesicles such as stability, fluidity, permeability can be easily tuned due to the rich chemistry of block copolymers. In this talk, I will discuss the facile one pot synthesis of polymeric vesicles made of amphiphilic diblock copolymers through light mediated polymerization induced self-assembly and their potential applications. The growth of hydrophobic units at the end of hydrophilic chains forms an amphiphilic block copolymer that can undergo self-assembly in aqueous solution. By varying the molecular weight of the two blocks, higher order morphologies can be obtained.