Monocular parallax

Monocular parallax is when a single eye rotates and the perspective shifts in that eye as a result. This happens because the optical center of the eye is not the same as its rotational center. It is also simply called ocular parallax. It is not to be confused with motion parallax.

It can easily be seen by putting your finger in front of your eye, 2 centimeters away, and having a computer screen 1 or 2 feet away showing a picture. Have only one eye open, then rotate your eye left and right, and you will see the blurry edge of your finger moving relative to the computer screen picture, just by moving your eye.