A tilted-wear type contact lens (10, 60, 80, 90) comprising an optical zone situated in a lens center section, and provided with a first diopter power region (26, 82) and a second diopter power region (24, 84) having a lens diopter power that is more positive than that of the first diopter power region (26, 82), wherein a superficial center (30, 32) of at least one of the first diopter power region (26, 82) and the second diopter power region (24, 84) is decentered on a symmetrical meridian, defined by one diametrical line of the optical zone, against a geometric center of the optical zone, and a circumferential positioning member (40, 42, 44, 46, 62, 64, 68) is provided to afford stable positions in a lens circumferential direction when worn in an eye, wherein an orthogonal meridian that is orthogonal to the symmetrical meridian is tilted by a prescribed angle with respect a vertical line of the eye, characterized in that: the contact lens (10, 60, 80, 90) has a lens profile that is axisymmetric with respect to the symmetrical meridian, the circumferential positioning member (40, 42, 44, 46, 62, 64, 68) is adapted to give rise to a first stable state in which, with the lens placed in a right eye, the orthogonal meridian is tilted by a first tilt angle in the circumferential direction relative to the vertical line of the eye, and to a second stable state in which, with the lens placed in a left eye with an orientation thereof flipped vertically from that when worn in the right eye, the orthogonal meridian is tilted relative to the vertical line of the eye by a second tilt angle to an opposite side in the circumferential direction from the first tilt angle, and a visible indicator mark (48, 70) is provided for identifying normal position and flipped position in relation to the orientation in a lens vertical direction, wherein: the tilted-wear type contact lens (10, 80, 90) further comprises a peripheral zone disposed to an outer peripheral side of the optical zone, wherein the circumferential positioning member (40, 42, 44, 46) comprises two slab-off zones (40, 42) provided on respective portions of the peripheral zone located at opposite sides of the optical zone in a direction of the orthogonal meridian, the two slab-off zones (40, 42) are made thinner than portions located at opposite sides of the optical zone in a direction of the symmetrical meridian, and the two slab-off zones (40, 42) are axisymmetric with respect to the symmetrical meridian and non-axisymmetric with respect to the orthogonal meridian. the contact lens (10, 60, 80, 90) has a lens profile that is axisymmetric with respect to the symmetrical meridian, the circumferential positioning member (40, 42, 44, 46, 62, 64, 68) is adapted to give rise to a first stable state in which, with the lens placed in a right eye, the orthogonal meridian is tilted by a first tilt angle in the circumferential direction relative to the vertical line of the eye, and to a second stable state in which, with the lens placed in a left eye with an orientation thereof flipped vertically from that when worn in the right eye, the orthogonal meridian is tilted relative to the vertical line of the eye by a second tilt angle to an opposite side in the circumferential direction from the first tilt angle, and a visible indicator mark (48, 70) is provided for identifying normal position and flipped position in relation to the orientation in a lens vertical direction, wherein: the tilted-wear type contact lens (10, 80, 90) further comprises a peripheral zone disposed to an outer peripheral side of the optical zone, wherein the circumferential positioning member (40, 42, 44, 46) comprises two slab-off zones (40, 42) provided on respective portions of the peripheral zone located at opposite sides of the optical zone in a direction of the orthogonal meridian, the two slab-off zones (40, 42) are made thinner than portions located at opposite sides of the optical zone in a direction of the symmetrical meridian, and the two slab-off zones (40, 42) are axisymmetric with respect to the symmetrical meridian and non-axisymmetric with respect to the orthogonal meridian. the tilted-wear type contact lens (10, 80, 90) further comprises a peripheral zone disposed to an outer peripheral side of the optical zone, wherein the circumferential positioning member (40, 42, 44, 46) comprises two slab-off zones (40, 42) provided on respective portions of the peripheral zone located at opposite sides of the optical zone in a direction of the orthogonal meridian, the two slab-off zones (40, 42) are made thinner than portions located at opposite sides of the optical zone in a direction of the symmetrical meridian, and the two slab-off zones (40, 42) are axisymmetric with respect to the symmetrical meridian and non-axisymmetric with respect to the orthogonal meridian.