Coming straight ... and going down

“Binocular vision is quite good for working out where objects are in space,” said Andrew E. Welchman, the lead author of the study and a lecturer at the University of Birmingham in England. “Because you have two eyes, the brain can take signals from each and compare them over time, averaging them. But when you have an object coming toward you, the differences in the information you get from the left and right side are more subtle,” and this makes the decision on location and speed more difficult.