Not an expert, but you actually focusing on a pixel is your brain doing image processing, not a function of your eyeball. Your field of vision (and focus) is m

Not an expert, but you actually focusing on a pixel is your brain doing image processing, not a function of your eyeball. Your field of vision (and focus) is much bigger than 1 degree, so any part of the image that you are "looking at" is something the brain is doing to the image as post processing, not something your eyeball is doing.