Disclosed is a contact lens including an optical zone having a substantially circular shape; an peripheral zone having an annular shape and located around the optical zone; and an intermediate zone having an annular shape and located between the optical and peripheral zones. The intermediate zone including a convex portion formed in at least one radial position of a back surface thereof so as to extend in a circumferential direction thereof with an outwardly curved surface as seen in a diametrical cross-section of the lens.