disclosed is a dimmable safety mirror which is adaptable for mounting over a conventional motor vehicle mirror . the safety mirror comprises a dimmable mirror subassembly having a surface selectively switchable between at least a high reflectance state and a low reflectance state and a mounting mechanism for attaching the dimmable mirror to the conventional mirror in a manner to make the dimmable surface a viewing surface of the safety mirror . in the case of a power loss , the dimmable mirror subassembly can be quickly and easily removed to make the conventional mirror the viewing surface .