1 - center your head on the screen
2 - close your left eye
3- stare at the ball with your right eye
4- on your peripheral vision see what happens to the cross
All human beings have blind spots, one in each eye, where the optic nerve leaves the retina. In fact, all vertebrates do. If the test isn't working for you, you just need to adjust the level of your head and your distance from the screen.
Well...
How far shoud my head be from the screen then because it doesnt dissapear other than thay....
EDIT:
AHHHHH
I just sat back in my chair and did it, sure enough it worked.
thats scary
All human beings have blind spots, one in each eye, where the optic nerve leaves the retina. In fact, all vertebrates do. If the test isn't working for you, you just need to adjust the level of your head and your distance from the screen.