Here is a fun little experiment you can do while walking home today that shows how much you depend on having two eyes.
Pull your keys out of your purse or pocket. While walking at a normal pace, toss your keys up about a foot over your head. Tilt your head toward the place where the keys stop going up and start coming down. Keep walking, don’t move your head, leave your arm at waist level and catch the keys.
I’m not particularly coordinated, but when I did this I was surprised to see that I could catch my keys more than 9 times out of 10, even though I couldn’t see the keys for the last few hundredths of a second as they fell.
Now try the same thing, but with one eye closed. Your results will vary, but my success rate fell to 1 in 5. Often I didn’t even manage to touch my keys on the way down.