An interior rearview mirror assembly for a vehicle includes a mirror casing and an electro-optic reflective element assembly disposed at the mirror casing. The front substrate of the reflective element has a first surface and a second surface and a perimeter edge between the first and second surfaces. The second surface of the front substrate has a transparent conductive coating established thereat. The rear substrate of the reflective element has a third surface and a fourth surface and a perimeter edge between the third and fourth surfaces. The third surface of the rear substrate has a conductive coating established thereat. With the electro-optic reflective element assembly disposed at the mirror casing, the perimeter edges of both the front and rear substrates are exterior the mirror casing and provide a curved transition between the first surface of the front substrate and an outer surface of the mirror casing.