Provided is a photocurable resin composition having low viscosity, and with which a high refractive index can be achieved. Specifically, said composition employs a urethane (meth)acrylate resin (A) obtained by reacting, as essential starting material components, an aromatic diisocyanate compound (a), a polyol compound (b), and a hydroxyl group-containing (meth)acrylate compound (c). Said composition contains structural units (a-1) represented by structural formula (1) (where, R1 is a hydrogen atom or a methyl group) and structural units (a-2) represented by structural formula (2) (where, R1, R2, and R3 are hydrogen atoms or methyl groups, and X1 and X2 are hydrogen atoms or methyl groups), at a molar ratio [(a-1)/(a-2)] of 45/55 to 60/40, and the polyol compound (b) has an aromatic hydrocarbon backbone.