- Close your left eye and stare at the cross mark in the diagram with your right eye.
- Off to the right you should be able to see the black dot.
- Now slowly move toward the computer screen. Keep looking at the cross mark while you move.
- At a particular distance the spot will disappear (it will reappear again if you move even closer).
The fact that is disappears is because of your blind spot.The blind spot is the area on the retina without receptors that respond to light. Therefore an image that falls on this region will NOT be seen. It is in this region that the optic nerve exits the eye on its way to the brain.
Not gonna lie, one of the things that has always scared me is the thought of a creature that can exist in people’s blind spots. It just knows instinctively where the blind spot is, and is there all the time, right next to you.