It may surprise you to learn that there is a better way to set the rearview mirrors on your car. The quick test: if you look in your side mirrors and you see the side of the car, then you're not using the mirror's capacity! Essentially, most people have a huge overlap between the center and side rearview mirrors, which is unnecessary. By spreading your side mirrors you lose no information about what's behind you, but gain valuable insight into what's beside you.
The inside mirror
Adjust the inside mirror so you can see the entire rear window from the driver's seat. You should have to move only your eyes, not your head, when using this mirror.Drivers 6 feet tall or taller may find it helpful to reposition the mirror upside down, if possible. This usually raises the bottom edge fo the mirror about 1 to 2 inches and can substantially rescue a major blind area to the front for tall drivers.
To adjust the driver's side-view mirror, place your head against the left side window and set the mirror so you can just barely see the side of the car in the mirror's right side. To adjust the passenger's side-view mirror, position your head so that it is just above the center console. Set the mirror so you can just barely see the side fo the car in the left side of the mirror. If the vehicle is not equipped with remove mirror-adjustment controls, you may need assistance when properly positioning this mirror.With these settings, you will have almost seamless visual contact around your vehicle, which can help you detect the presence of nearby drivers. For example, when being passed by a vehicle in the lane to your left, you will see it progress from the rearview mirror, to the left side mirror and then to your side vision.
Before driving with these updated mirror settings, see how they work while your vehicle is parked. For example, you can parallel park along a street, then see how passing vehicles move through your mirrors and peripheral vision. This can help you become oriented to the new settings before heading out into traffic.
Remember, even properly positioned mirrors cannot eliminate all blind spots. To reduce risk, make a final check to the sides before attempting any lateral moves.
Link Source: Senior Driving
Image Source: Driving Test Tips