<P> Because of the distance from the driver's eye to the passenger side mirror, a useful field of view can be achieved only with a convex or aspheric mirror . However, the convexity also minifies the objects shown . Since such objects seem farther away than they actually are, a driver might make a maneuver such as a lane change assuming an adjacent vehicle is a safe distance behind, when in fact it is quite a bit closer . In the United States, Canada, India, Korea and Australia, non-planar mirrors are etched or printed with the warning legend objects in the mirror are closer than they appear . In Canada, this warning is often supplemented by a transparent decal on the passenger side window repeating the warning in French: les objets dans le retroviseur sont plus proche qu'ils ne le paraissent . In Korea, the warning appears in Korean . Warnings of this nature are not required in Europe . </P> <P> Most side mirrors may be manually or electrically folded in, to protect them when the car is parked or being washed in an automated car wash . Passing cars can easily clip protruding wing mirrors; the folding capability helps protect them from harm . </P> <P> Fender mirrors were used on all Japanese cars until 1983, when Japanese law permitted door mirrors for the first time . Despite this, a few Japanese - made cars for the domestic market in that country still have fender mirrors . </P> <P> U.S. Federal Motor Vehicle Safety Standard 111 requires that convex side view mirrors must have a curvature radius of between 889 mm and 1651 mm . Canada Motor Vehicle Safety Standard 111 stipulates a range of between 890 mm and 1800 mm . Neither the U.S. nor the Canadian standard allows for aspheric mirrors . The European ECE Regulation 46 used throughout most of the world permits planar, convex, and / or aspheric mirrors on either side of the vehicle . American research suggests non-planar driver side mirrors may help reduce crashes . </P>

When did cars start having two side mirrors