Exterior rearview mirrors on cars are typically convex, whereas interior rearview mirrors are usually flat.
Convex mirrors feature a spherical surface with varying radii of curvature. They produce images that appear smaller than the actual objects but offer a wider field of view-functioning much like a camera's "wide-angle lens"-which is why they are often referred to as wide-angle mirrors. This type of mirror is commonly used for exterior and downward-facing (curb-view) mirrors. Positioned on the left and right sides of the vehicle's front and inside the cabin, these mirrors reflect conditions behind, to the side, and below the vehicle, allowing the driver to indirectly monitor these areas. Acting as a "second pair of eyes," they expand the driver's field of vision; as critical safety components, their reflective surfaces, shapes, and adjustment mechanisms are carefully engineered.
For a wider view: Convex mirrors diverge light, enabling the driver to see a larger area and reducing blind spots.
Imaging characteristics: The image in the mirror appears smaller than the actual object, yet the field of view is expansive-resembling a camera's wide-angle lens-making it easier to monitor vehicles approaching from the side and rear.
Safety considerations: When reversing, changing lanes, or passing other vehicles on narrow roads, a wide field of view helps drivers spot surrounding vehicles and pedestrians early, thereby enhancing driving safety.