Are car rearview mirrors concave or convex?
3 Answers
Convex mirror. Principle: 1. When parallel light rays are projected onto a convex mirror, the reflected rays diverge. If these reflected rays are extended backward in the opposite direction, they will converge and intersect at a point behind the mirror's surface. This point is the principal focus (F) of the convex mirror, which is a virtual focus. 2. From a point (A) on the object, draw a line parallel to the principal axis as the incident ray. When this incident ray reaches the spherical mirror's surface, it reflects, and the reflected ray travels in the opposite direction. This reflected ray must pass through the principal focus (F). 3. From the same point (A) on the object, draw a line connecting to the mirror's center of curvature (C) as the secondary axis. The intersection point (A′) of this secondary axis with the reflected ray passing through the principal focus is where the image of the object is formed.
As a veteran driver with decades of experience, I can confidently tell you that car rearview mirrors are convex mirrors. These make me feel secure while driving on highways because the outward curve of convex mirrors expands the field of vision and eliminates blind spots. I remember driving an old car in my younger days with flatter rearview mirrors that offered a narrower view, and I nearly collided with adjacent vehicles several times while changing lanes. Nowadays, the standard design is convex mirrors—they slightly reduce image size but significantly increase coverage, especially during high-speed driving or urban traffic jams, allowing you to see more behind you. I often remind new drivers to adjust their mirror angles properly before setting off and to keep them clean for unobstructed vision. Safety comes first, and this mirror design is genuinely reliable in reducing unnecessary risks. Regularly checking mirror condition is key to maintaining smooth and safe driving.
When I first started learning to drive, I was quite curious about the shape of the rearview mirrors. After researching, I found out that cars use convex mirrors, not concave ones. Convex mirrors provide a wider field of view, making the entire rear window area appear larger from the driver's seat. My instructor explained that they deliberately distort the image to reduce blind spots, such as helping to notice approaching cars when changing lanes. Now that I'm used to driving, I find convex mirrors quite practical—though distant objects may appear smaller, they enhance overall safety. Concave mirrors magnify objects but have a narrower field of view, making them unsuitable for cars. In daily driving, I’ve developed good habits by adjusting the mirrors properly before every trip. For beginners, I recommend practicing with convex mirrors to observe the surroundings and avoid potential accidents.
