Purpose: The purpose of my experiment is to compare the Cow eye with the human eye and see the similarities and differences.

Hypothesis: If I see the structures of the cow’s eye, then I would be able to observe how the human eye functions.

Materials:

  • Preserved sheep eye
  • Scissors
  • Prod
  • Dissection tray
  • Protective gloves
  • Paper towel
  • Plastic disposal bag
  • Wear protective gloves. Follow your teacher’s instructions to take them on and off.

Procedure:

  1. 1. Examine the eye before any action.
  2. 2. Use scissors to cut off the muscles and fat.
  3. 3. When you have taken most of the protective fat off the eye that covers the sclera and around the eye you should then have a round and ball like eye.
  4. 4. Then you poke a hole through the sclera so that you may be able to cut the eye in half with scissors.
  5. 5. Cut all the way around the eye. Try not to harm anything inside while cutting.
  6. 6. After you cut, separate the two parts of the eye apart.
  7. 7. Use the prod again and make a hole between the sclera and the cornea.
  8. 8. Use the scissors and cut around the cornea and remove it.
  9. 9. Take out the lenses and clear it from the jelly substance.

10. Put all the pieces of the eye in a disposal bag and clean up your work space and your hands.

Observations: I saw that the retina, where pictures are made into electrical signals and sent to the brain. I also saw the optic nerve which send the electrical signals to the brain. The lens was yellow and less flexible because it was old. This proves that as people age their lens decreases in flexibility.

Questions:

1. A: Sheep have an oval shape pupil, and the humans have a circular one.

B: Sheep have 4 muscles to move their eyes up, down, left, and right. But we have six       muscles so that we can roll our eyes.

C: The cow’s eye is much tougher than the human’s eye.

D: The cow’s eye is always one colour

2. 

3. Because the eye’s lens was old, it was hard, solid (not too much), and yellow. It was a little like an oval shape. I tried to see through it but it was too old.

Conclusions:

–       In the cow’s eye, under the cornea, you would find the iris which is an oval shape. But in the human’s eye, the iris is circular. This shows that our eye accepts more light because the more circular the eye is, the more it lets light enter.

–       I found a jelly-like substance between the cornea and the pupil. I remembered that it helps the cornea stay in great shape.

–       I think my results were accurate because I did figure out facts about the human eye while observing the cow eye.

–       I think my observations were important because when I saw the shapes, sizes and colors, I understood more about the eye and why it functions in the certain way.


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