Under federal law, to use any devices which render inoperative the effectiveness of a federal standard would be illegal. In Mirror Are Closer Than They Appear . However, even bearing the warning about the visual distortion under federal law, without knowing how to safely operate the convex mirror, cannot actually help drivers safely judge the closing distances of other vehicles. Thus, bearing a warning under federal law to serve as a substitute of know-how for the mirror operation guideline defies federal law itself. Essentially, the visual defects produced by persistence of vision reflected in any kind of mirror are defective to the eye, regardless of the size of the images and of the mobile objects.
Blind spot is the by-product in the operations of the plane rearview mirror systems.
If you do not physically turn your head, you will never see the vehicle when you change to that lane. To prevent you from getting in the way of vehicles in that lane and to know if someone in another lane may plan to move into the same spot you want, you must physically turn your head for a check that creates a new blind spot in your forward visual field to impair your front view. It gives you three broken tunnel images of traffic. It is difficult to scan three reflecting surfaces of the mirrors at three different directions to piece together three discontinuous tunnel images in a split-second glance. Most importantly, each tunnel image is surrounded by complete darkness.