Thankful Day #19

Thankful Day #19: I am thankful for stereopsis. First described by Sir Charles Wheatstone in 1838, this is the perception of depth resulting from two slightly different images from distant objects being projected on our two retinae. It is not identical to the colloquial sense of "depth perception," however, since one-eyed people (yes, you, Cyclops) still have many cues for relative distance (e.g., overlap, size, light diffusion).