What is tunnel vision?

Tunnel vision means that the field of vision shrinks, and that you only have focus straight ahead. It can also be linked to speed blindness, where high speed can also cause problems for you as a road user out on the road. At long distances and at high speeds, speed blindness can occur, which means that the ability to judge one's own speed is impaired.

You do not feel that the speed is high, but instead you think that the car is traveling significantly slower than what actually happens. The whole thing can lead to the braking distance being misjudged and you braking too late, which can lead to serious accidents.