The present invention relates to an adhesive composition for optical use, which is applied to optical devices or display devices and thus may exhibit excellent adhesion performance while exhibiting a high barrier performance based on a low water vapor transmission rate, and may implement both excellent optical characteristics and durability, and specifically, provides an adhesive composition for optical use, the adhesive composition including: a thermally curable rubber including an isobutylene-isoprene rubber having a carboxyl group and an isobutylene-isoprene rubber having a hydroxy group; and a thermal crosslinking agent. Further, the present invention provides an adhesive film for optical use, including an adhesive layer including photocured products of the adhesive composition for optical use.