It's not really depth perception, but there is a significant difference in how objects are perceived when looking with both eyes. It's also applicable to binocular splitters used with a single mirror/lens telescope.
Your brain can also do 1+1 and end up with 2.5 or even 3 in the brain :) I have really bad eye sight on both eyes, one can not see enough alone but both together see much better than I would expect on the same distance.
