Body & HealthFact
Each eye is missing a patch of image, and you never notice.
Where the optic nerve leaves the retina there are no light-sensing cells. This blind spot sits about 15 degrees to the side of centre and spans roughly 5 to 7 degrees, wider than the full moon. You still see no hole, because the brain fills the gap with the surrounding pattern and the other eye usually covers it.
Useful: Your vision is a reconstruction by the brain, not a camera recording.
Source: en.wikipedia.org