Vision is arguably the single most important sense that human beings (and most other animals) possess. Most people use sight to judge every aspect of their lives and many fashion designers and artists rely on their vision—and other people’s vision—to earn a living by creating things that are beautiful to look upon. Since the human eye can distinguish approximately ten million different colors, shades and hues have played a big role in the way that human beings decorate themselves and things in their societies. Vision is also central to storytelling, warning systems and interpersonal communication since reading facial expressions and body language relies on sight. Hence, taking care of your eyesight—such as wearing sunglasses in bright sunlight and getting yearly exams—is extremely important.
Below are some facts about eyes:
• You blink about 12 times every minute.
• Your eyes are about 1 inch across and weigh about 0.25 ounce.
• Some people are born with two differently colored eyes. This condition is heterochromia.
• Even if no one in the past few generations of your family had blue or green eyes, these recessive traits can still appear in later generations.
• Each of your eyes has a small blind spot in the back of the retina where the optic nerve attaches. You don’t notice the hole in your vision because your eyes work together to fill in each other’s blind spot.
• The average blink lasts for about 1/10th of a second.
• While it takes some time for most parts of your body to warm up to their full potential, your eyes are on their “A game” 24/7.
• Eyes heal quickly. With proper care, it only takes about 48 hours for the eye to repair a corneal scratch.
• Seeing is such a big part of everyday life that it requires about half of the brain to get involved.
• Newborns don’t produce tears. They make crying sounds, but the tears don’t start flowing until they are about 4-13 weeks old.
• Around the world, about 39 million people are blind and roughly 6 times that many have some kind of vision impairment.
• The cells in your eye come in different shapes. Rod-shaped cells allow you to see shapes, and cone-shaped cells allow you to see color.
• Out of all the muscles in your body, the muscles that control your eyes are the most active.
• 80% of vision problems worldwide are avoidable or even curable.
• Doctors have yet to find a way to transplant an eyeball. The optic nerve that connects the eye to the brain is too sensitive to reconstruct successfully.