Did you know that the eyes themselves are not what actually allow you to see? They are simply a conveyance for messages sent from the brain, via the optic nerve.

Similarly, did you know that only one-sixth of your eye is even visible to the outside world? Or that your eyes are comprised of more than two million intricately connected working parts?

And that’s just the beginning! Here are 15 fascinating facts about the eyes.

1. Your eyes focus on 50 different objects every second.
2. The only organ more complex than the eye is the brain.
3. Your eyes can distinguish approximately 10 million different colors.
4. It is impossible to sneeze with your eyes open.
5. Ommatophobia is a fear of the eyes.
6. 80 percent of all learning comes through the eyes.
7. Your eyes can detect a candle flame 1.7 miles away.
8. Your iris (the colored part of your eye) has 256 unique characteristics; your fingerprint has just 40.
9. Heterochromia is the medical term for having two different colored eyes.
10. Only 1/6 of your eyeball is visible.
11. Your eyes are comprised of rods and cones. Rods allow you to see shapes, while cones are responsible for detecting and deciphering colors.
12. The average person blinks 12 times a minute (bet you just blinked!).
13. The shark cornea is nearly identical to the human cornea, and has even been used in human eye surgery!
14. Your eye is the fastest contracting muscle in the body, contracting in less than 1/100^th of a second.
15. The optic nerve contains more than one million nerve cells.