The principle of "no blind spot" rearview mirror is not complicated, and it is a convex mirror optically. Compared with the plane mirror, the convex mirror with the same size has a larger field of view, but the imaging of the observed object becomes smaller. The greater the curvature of the convex mirror, the larger the field of view, but the greater the deformation of the object.
After installing the convex rearview mirror in the car, the driver's field of vision will be wider, and more objects can be observed in the rear, but because the objects are "smaller", the distance illusion will be caused to varying degrees. Therefore, when choosing a rearview mirror, we can't simply think that the bigger the field of vision, the better.
There are three main types of "no blind area" rearview mirrors sold in the market:
Attach a small mirror: usually a small round lens, which is convenient to install. Just remove the tape from the back and stick the small mirror on the original flat rearview mirror. Driving during the day can barely be used, which can broaden your horizons.
However, due to the large arc of this small mirror, the oncoming car seen from behind becomes very small, which will produce a serious distance illusion. When merging, the car coming from the rear is very close, but it is mistaken for being far away and very unsafe. Driving at night, you can only see some small bright spots in the rear, and you can't tell whether it is a car light or a street light, and you basically lose the function of looking at the rearview mirror.
"No blind spot" rearview mirror: it is a substitute for the rearview mirror in the trunk, which is much wider than the original mirror and has a certain curvature. This kind of rearview mirror is used in the car, and you can see the range about the width of the car through the rear window, which is convenient for reversing and helpful for merging lines.
This rearview mirror is easy to install, as long as it is attached to the original mirror. Some products are also equipped with small ornaments such as guide balls, which are both beautiful and can indicate the driving direction. Correct selection and use of "no blind area" rearview mirror can broaden the rear view and facilitate driving.
However, the so-called "no blind area" only broadens the field of vision compared with the flat mirror, and it cannot be simply thought that you can gain insight into everything by installing the "no blind area" mirror.
In addition, convex mirrors will reduce the image of the objects behind more or less, resulting in a wrong sense of distance. Therefore, it is not recommended to replace all rearview mirrors with convex mirrors, but at least one plane mirror should be kept to ensure the correct distance reference.