The eye can actually differentiate 500 different shades of gray....a few more than 50.
The eye is the second most powerful organ in the body....the brain being the first.....and utilizes 65% of brain power.
Newbornes don't make tears until they are 4 to 13 weeks old. Doesn't mean they don't still cry as any parent would tell you.
The eye heals quickly. Most cuts to the cornea will heal in less than 48 hours.
The pupil is actually a hole that you can look inside the body and see blood vessels and the optic nerve.
The images sent to the brain are upside down and backwards. If you put on glasses that turn your world upside down, the brain adjusts to accommodate what it sees.