Question

Now repeat this procedure while looking at the "X" in the lower panel. When the

Answer 1

Answer:

The mouse disappears and bars seen only instead of the disappearing of the cage as the image falls on a blind spot in this blind spot test by looking X with one eye in the lower panel. It happens due to optical illusion where the brain compensates with missing information on its own and completes the cage as the brain fills the missing data in a regular pattern. Thus, the mouse disappears from the cage, and only bars are seen.

The brain has the ability to complete the missing part of the image as the visual field of the two eyes overlap therefore with open eyes there is no blind spot precieved.