Eye Project for science

THE WONDERFUL WORLD OF THE EYE......

By Brittany Yasay, Eva Maina, Stefanie Yupanqui, Celia Ontieror


The human body...what a great adventure. Of course all of us were born with ten fingers and ten toes, an arm, and a leg, maybe. But one of the most essential necessities that we use all day, everyday is, well, our eyes. But as we age our eyes weaken and start to develop different types of eye diseases.





Our eye is make up of tons of parts just like our body. The most outer part of the eye is the cornea, the transparent outer coating. The cornea is the part of the eye that focuses the light that enters the eye. Just behind the cornea is where pupil and the iris sit. The pupil is the main opening of the eye that allows light rays to enter. The iris is the part of the eye filled with color. Not only does it give the color, the muscles below it contract and expand the iris to control the amount of light that passes through. After the pupil and the iris is the lens. The lens focuses the light that is passed through the iris and the pupil to the light sensor cells on the back of the eye. The back of the eye is called the retina, which contains rods and cones. Rods and cones are the light sensitive nerve ending that convert the light into electrical signals that are sent to the brain by the optic nerve.


On the outside of our eye, it doesn't seem like a whole lot of "important essential". Well, the outer eye is the section of the eye where it allows light to be passed through and focused at the retina. But sometimes it focuses a bit earlier. That's called nearsightedness or Myopia, which means the person can see near by objects more clearer than farther objects. The best kind of glasses to get to correct this problem is to use glasses with concave lenses or refractive surgery. The concave lens help the image reach the retina on time. Another eye problem us people can develop is farsightedness or hyperopia, which means that the person sees nearby objects blurrier than farther objects. Farsightedness is when the image is focused behind your retina. To correct farsightedness, all you need is eye glasses with convex lenses or if you're a person who needs to be more satisfied, you can get refractive surgery. Last but not least, astigmatism. Astigmatism is usually when your cornea is irregularly shaped. You can correct astigmatism with contact lens, glasses, or LASIK surgery.



Lenses. Yeah, the clear thing that is sitting in your eye glasses. Did you know that there is 2 types of lenses? Probably not. One type of lens is called concave lens, also called diverging lenses. Concave lens are lenses that are curved inward and wider at the edges. These lenses cause light rays to spread out and only form virtual images. Another type of lens is called convex lenses, or converging lenses. These lenses are wide at the at the center and narrower at the edges. Convex lens form real or virtual images.

Imagine yourself in a dark room playing with a flashlight. You flash the light toward the mirror and suddenly see it behind you on the back of your wall. That event is called the law of refraction. Refraction is when a light ray is bent at an angle.

TYPES OF EYE DISEASES:

1. Glaucoma

• It is caused when dangerous build up of the internal eye pressure
• In the U.S., about 2.5 million Americans have this eye disease
• It's the second leading cause to blindness
• Treatment: Glaucoma surgery or eye drops that contain glaucoma medication

2. Pink Eye (Conjunctivitis)

• Usually caused by allergic, viral, or bacterial reasons.
• Because of their poor hygiene, young children tend to have pink eye more than adults do
• Treatment: Antibiotic eye ointments

3. Macular Degeneration

• It's the leading cause of vision loss in Americans 65 or older
• About 1.75 million people have this eye disease in the U.S.
• caused when the macula, which is the part of the retina that gives clear vision, starts to degenerate.
• Linked with people who are aging, obesity, heredity, high blood pressure, smoking, lighter eye color.
• Treatment: FDA-approved drugs of Lucentis, Macugen and Visudyne used with Photodynamic Therapy or PDT

(Picture on the right: How thing look when you have Macular Degeneration)

4. Cataracts

• It's the clouding of the eyes natural lens
• Having our lens made up of water and protein, the protein, as we age, the protein clump together
• An estimated 3 million people in the U.S. have this eye disease
• Treatment: Glasses, Cataract surgery (removal of the clouded lenses and replaced with clear lens)
  

Overall, the eye is probably the most complex organ in the human body. As we age, our body parts starts to age with us, too. Some how, our age affects our eyes in a lot of ways. When were young, we might have an eye problem, like nearsightedness or farsightedness, but when we start to age and grow, our eyes develop diseases, like cataracts or macular degeneration. Even though these diseases and problems don't have cure, all we can do is try to keep our vision as healthy as possible.