The Opening to Your Soul
How Human Eyes Let Us See the World
by Reece McAndrew, age 13
Some say the eyes are the opening to the soul. They are also the opening to the world. Without your eyes you wouldn’t be able to see anything. Everything in your eyes has a purpose.
Your cornea is what protects the insides of your eye. Your cornea functions as a secondary lens. You are lucky to have your cornea protecting your eye.
The iris in your eye is a muscle that controls the amount of light that goes into your eye. In bright light your irises expand so your pupils become smaller. In dark light your irises contract so your pupils become larger.
Behind the iris is the lens. The lens is just like the lens in a pair of glasses except rounded. The lens reflects light into the retina. The lens reflects light in such a way that the image appears upside down. After the light hits the retina, the retina turns it into an image.
Cones and rods in the retina detect different features of the image. Rods, the more sensitive, detect how bright the image is. Cones, the less sensitive, detect what colors are in the image.
After the retina detects an image, it goes to the optic nerve. The image then goes straight to the brain. The brain then flips the image right side up.
The eyes, although very complicated, are also very useful. Eyes let you see details of different objects that without them, you would never know existed. The reason people have two eyes is because two eyes allows you to see in three dimensions.
Having two eyes also gives you depth perception. Depth perception helps you see the distance objects are away from you. Sometimes one of your eyes can be stronger than the other. This can affect your depth perception and causes you to misinterpret distances. Overall your eyes are a very important part of your life. And they are also very interesting objects.
[Source: The Big Book of Knowledge]