Our five senses help us to understand our surroundings by seeing, hearing, smelling, tasting, and touching. The senses work together to give us the clearest picture possible of what is happening around us. If one of our senses is not working correctly or at all, our other senses will work harder to make up for the missing one. Let's talk about that first one....seeing! The eye is an incredible part of our body. It is working from the moment we open our eyes in the morning, until the moment we close them at night to go to sleep. They help you to see all sorts of things like colors, shapes, people, light, and more. Imagine if we didn't have eyes and all of the fun things we would miss out on seeing. A baseball game, an art project, your puppy running around the yard, and your smiling reflection in the mirror. We owe a lot to those marvelous eyes, so let's start by understanding how they work!
How Do We See?
Our eyes find images and light then turns them into electrical messages for our brain to understand and process what we are looking at. Our eye process is much like the operation of a camera if you think about it. And a fun fact is that the camera was actually designed long ago with the idea of the human eye in mind. First, the pupil begins by absorbing the light into your eye. Then, it goes to the retina at the back of your eye. This is the most sensitive part of your entire eye. When the light hits the retina, it takes a mental upside down picture of what you are looking at. Then finally, the optic nerve carries the upside down image to the brain to be flipped and understood by you. Why do we have two instead of one? By having two eyes, it gives us the ability to see things in 3D (three dimensional). Everyone's eyes are a little bit different in color, shape, and how well they can see. Some people need to use corrective lenses such as contacts or glasses to help their eyes to see a little bit better. And some people have trouble telling the difference between colors when they are looking at an image. This is called color blindness.
Biology of the Eye
- Cornea: This is the outer most layer of your eye. It helps to focus your vision.
- Iris: This is the colored circle that surrounds your pupil. When someone refers to eye color, this is the part that they are referring to. (Ex. Blue, Brown, Green, Hazel)
- Pupil: This is the black opening in the center of your eye which allows light to come through and be absorbed.
- Sclera: This is the white part of your eye that goes around the iris. It is composed of connective tissue and provides strength to the entire eye.
- Lens: This is the clear disc shape that is located behind the pupil and it's main job is to focus the light.
- Retina: The Retina is located on the back wall of the eye and completely made up of nerve cells. It absorbs the light and turns it into a message the brain can understand.
- Rods and Cones: Rods act when you are in a low light level and help us to see better at night. Cones act when you are at a higher light level and help us to see different colors.
- Fovea: This is the tiny pit in the retina which allows the clearest vision to come through.
- Optic Nerve: The optic nerve is located in the back of the eye, it's job is to transport information from the retina to the brain by electrical impulses.
- Macula: This the functional center of the retina. The Macula gives us the ability to see and read details while the Retina is more for seeing peripheral vision.