The invention relates to a contact glass for ophthalmic surgery. Said glass comprises a lens body that is held in a frame and a front lens surface that is designed to be placed against the eye. According to the invention, the front lens surface is concave and follows a surface curvature (K) and an annular gap is formed at the edge of the front lens surface between the lens body and the frame, said gap being used to apply a negative pressure in order to fix the contact glass to the eye. The frame is designed to follow the contour of an imaginary continuation of the surface curvature (K), or at least does not project beyond the latter.