Where Does It Look Like Your Nose Is?
Following the suggestion of H. Ono et al. in their weird and fascinating 1986 article on "Facial Vision" in Psychological Research, I drew two lines on a piece of cardboard, and you might want to do the same. The lines start at one edge, about 6 cm apart, and converge to a point at the other edge. (A piece of paper held the long way will work fine, as long as you can keep it rigid.) Hold the midpoint of the 6 cm separation at the bridge of your nose and converge your eyes on the intersection point. If you do it right, it should look like there are three or four lines, two on the sides (one going toward each ear) and one or two in the center, headed right for the bridge of your nose.
The weird thing of course is that there are no lines on the cardboard that aim toward your ears or terminate at the bridge of your nose. Ono et al. suggest that the explanation (of the nose part at least) is that from the perspective of each eye the nose appears to be at the location of the other eye, so that the line headed toward your left eye seems to your right eye to be headed toward your nose and the line headed toward your right eye seems to the left eye also to be headed toward the nose.
With that in mind, I remove the cardboard and close one eye. Where does it seem that my nose is? Well, at first I'm inclined to say my perception is veridical: To the open eye, the nose seems closer than does my closed eye (or my bodily map of where my closed eye should be). But now I open and shut each eye in alternation. It does seem that my nose jumps around, maybe an inch or two side to side when I do this. But maybe that's just because my assumed egocentric position changes, relative to my nose?
Ono et al. also suggest trying to locate your phosphenes with one closed eye. (I had a post on this some time ago.) Phosphenes are those little circles you can see when you press on your eye. I find them easiest to see when I press on the corner of a closed eye and attend to the opposite corner of that same eye, looking for a dark or bright circle. (It may take some trial and error to get this right.) As I noted in the old post, for me at least the phosphenes generated by pressing the outside corner of a closed eye, with the other eye open, appear to be spatially located inside or behind the nose. This seems to me to be the case no matter which part of my closed eye I press. At the time of that post, it didn't occur to me that this might be because my nose was subjectively located as co-positional with the closed eye. Holding my nose with two fingers and pressing my closed eye with another finger from the same hand, to throw some tactile feedback into the mix, doesn't seem to change anything.