UPDATE: For anyone interested, I have proven to my own satisfaction that the effect is eye-specific. That is, the left eye is the only eye which sees the left eye with a "hovering pupil effect", and the right eye is the only eye which sees the right eye with a "hovering pupil effect". This can be established by holding up one hand and aligning one fingertip to cover one pupil in the reflected image. Even though both eyes remain open, and both eyes can be seen in the mirror, only one eye is seen to have the hovering pupil effect, like this: BEFORE: Please Register or Log in to view the hidden image! AFTER: Please Register or Log in to view the hidden image! The reason the fingertip does not appear to cover the pupil in the drawing is because this image is what the right eye sees. Due to parallax, the right eye does not see the fingertip covering the pupil, as it appears just slightly misaligned. But the left eye does see the fingertip covering the pupil, which makes the "hovering pupil effect" disappear.