A curable composition is provided which includes an oligomer having a plurality of pendent and / or terminal ethylenically unsaturated, free-radically polymerizable functional groups, a free-radically polymerizable crosslinking agent, and / or a diluent monomer, and a photoinitiator. The composition, when cured, is non-yellowing, exhibits low shrinkage and low birefringence making it suitable for many optical applications such as optical lenses, optical fibers, prisms, light guides, optical adhesives, and optical films.