double curvature outside rearview mirror means have a position of about 1/3 of a broken line. Smaller than the radius of curvature of a broken line, is mainly used to observe body side of the case remote location, within a broken line, large radius of curvature, to a position close to the body side when viewed, the combination of the two can be minimized curvature mirror the blind spot.
“double curvature rear-view mirror.”