They should have sent a poet.
But they didn't, they sent me instead.
So in the full light of all the bad poetry I've used to describe the sensation of adding depth perception to your ocular arsenal, I will try once again to explain what exactly it IS as an experience. I will use all of the scientific acumen I have to provide a clinical, factual account of the experience of depth perception.
I can't. I have no science for this experience. All of my words to describe it revolve around the concept of "feelings", "gut instincts" or, "just KNOWING" something. Is there a Scoville scale for depth perception?
My experience of depth perception is not one of seeing something additional, but of having my brain impose additional information upon what I already saw. I can point at myself in the mirror, and know without additional information that the finger in the mirror was separated in three-dimensional space from the shoulder of the arm attached to that finger. Based on the combined information of the two eyes, the brain can - not always perfectly - replicate a 3-dimensional arrangement of the things in view.
The perception of three dimensional space is not consumed as additional visual information. It informs the visual information. It is inherent in the visual experience. The knowledge of depth is not represented with any additional content provided by the external world, but as interpreted by the brain. This knowledge is immediately implicit in every interaction with the world.
Prior to having depth perception, when I would point point at myself in the mirror, I knew my finger was in front of me because it was attached to me, and because I know what it looked like to have a finger pointed at me. To me this came with the knowledge that the finger was far in front of its possessor, since I knew from accumulated experience that the shortening of the arm meant it was pointed at me and not toward the side. The same way I knew that when I saw a similar pose in a photograph, or even comic book.
Now, with the awareness of 3-dimensional space, it is the same finger pointing at me in the mirror, and visually looks exactly the same as without depth perception, but my brain has deduced from the input of both eyes that the finger is ahead of the holder.
Alignment of the eyes is essential for depth. The two eyes need to work together to ignite the neurons responsible for processing that internal 3d map.
In other words, I got a performance upgrade, and can now use the 3d chip in my GPU.
As a quick personal update, depth has returned regularly, and has taken on a bit mellower a quality for me in many situations, which is a good thing actually. The world still feels newly arranged in 3-dminesional space, but in a mellower suggestion. The brain is still learning to process the various images of my surroundings to present an interpreted version of 3d reality. Or at least, that's how it seems. So I can vibe the volume of the room around me now, when before I was more focused on the lamp or overhead fan. It has more fully insinuated itself into my visual perception. It's more solid when it is on. I do get the sensation that I'm still generating the kind of information my brain needs to be able to replicate that mental 3d map of my surroundings.
I'll be off and on the next few weeks, but will try to have some good updates when I do post. More soon!