Periscopes And Night Vision
The driver navigates the M1 Abrams by using three periscopes, also known as vision blocks. They can also substitute one of the periscopes for a night vision sensor if the crew is performing night operations. The periscopes allow the driver to have up to a 120-degree field of view in the tank. When operating the vehicle, the driver also has to be aware of behind them since they do not have a rearview angle.