Abstract The present invention provides a rear viewmirror for a motor vehicle which is automatically adjust-able to prevent the effects of dazzle eg. by a vehicleapproaching from behind at night. The mirror comprisesan adjustable mirror surface (2) housed in a casing (3)and connected in an adjustable manner to an actuator (8)which engages an annular ram formation (26) having variouscam profile heights whereby the mirror surface (2) can beadjusted by tilting. The cam formation (26) is part of atoothed wheel (11) driven by a small electric motor (21)the control circuit of which is actuated by a photosensor (38) so that mirror tilting is dependent on light intensitythresholds. The arrangement enables the various mirroradjustments to be achieved using uni-directional rotationof the motor and the toothed wheel (11) and this has theadvantage of providing more reliable operation with lessnoise. The present adjusting mirror is also relativelyinexpensive to manufacture.