Fast Facts about the Eyes

By Jocelyn Sun

Location:

The eyes are located in your eye sockets. The eye sockets are on the middle-front part of the skull. It is about the size of a Ping-Pong ball.

System:

The eyes are in the nervous system. The nervous system lets you see, touch, hear, taste, and smell.

Function/Purpose:

The eyes are the organs that let you see. You could still live without the eyes, though.

Performing Function:

The eye is made up of three layers. The sclera is the protective layer on the outside of the eye. The choroid contains the blood vessels that carry nutrients and oxygen to the eye. The retina is the light-sensitive layer that is part of the nervous system tissue.

The part of the eye that lets in light is called the vitreous humor. It also lets the eye keep its round shape. The cornea helps the eye focus light, though you cant see the cornea. Behind the cornea is the aqueous humor. The cornea and aqueous humor form an outer lens. The outer lens bends the light when it travels through the eye. Most of the eyes focusing work is done here. The iris is behind the aqueous humor. It controls how much light goes into the eye by growing bigger or smaller. The lens is behind the iris. It also focuses light. The lens changes shape to see farther or nearer. Next is the retina. The retina has a lot of rods and cones. Rods and cones let us see color by sensing the color. The retina sends signals to the brain through the optic nerves, which carry the signals to the brain. The brain flips the picture right-side up, because the eye actually sees upside down.

Diseases and Symptoms:

1. Astigmatism: The image will be blurry.

2. Myopia: Nearsightedness, which only lets you see images closer to the eye.

3. Hyperopia: Farsightedness, which only lets you see far away.

4. Cataracts: The image cant be seen clearly or cant be seen at all. Cataracts are like blindness. Cataracts form in the lens.

5. Color Blindness: The eye confuses colors. More boys have color blindness than girls.

6. Conjunctivis: The eye has redness, pain, and/or swelling.

7. Dacryostenosis: There is a blockage of the tear drainage system.

These are only some diseases!

Is There a Prevention for the Disease:

1. Cataracts: There is no prevention.

2. Color Blindness: No prevention.

3. Conjunctivis: Yes, you can have eye drops.

4. Astigmatism: No, but the person can wear glasses or contacts.

5. Myopia: No, but you can wear glasses or contacts.

6. Hyperopia: No, but you can wear glasses or contacts.

7. Dacryostenosis: No.

Vital/Non-vital:

The eyes are non-vital. If they were removed, you could still live, although you would not be able to see. If only one eye was removed, your blind spot would be longer.

Alcohol Effects:

If a person drank too much alcohol, he or she might have blurry vision, double vision, reduced vision, or eye redness.

Questions I Still Have About the Eyes:

1. Does hyperopia have anything to do with being hyper?

2. How does the Braille alphabet work?

Bibliography

Websites:Dowshen, Steven. Your Eyes. Kids Health. Nov. 2009. Web. 22 Feb. 2012 http://kidshealth.org/kid/htbw/eyes,html?tracking=K_RelatedArticle#7Bedinghaus, Troy. How does drinking alcohol affect your eyes?. About.com. 12 July 2010. Web. 22 Feb. 2012. http://vision.about.com/od/eyeexaminations/f/How-Does-Drinking-Alcohol-Affect-Your-Eyes.htm.Books:Treays, Rebecca, et al. Understanding Your Senses. Broadway, NY; Scholastic Inc., 2004