1. COW EYE DISSECTION
Use this presentation as your “virtual” cow eye dissection, or
use it as a guide for your actual classroom dissection
(recommended).
If you are following along at school, please be careful.
Scalpels and razors can cut you as easily as they cut cow eyes.
You can order cow's eyes at a butcher shop or purchase them
directly from a slaughterhouse. Try to get eyes with the
muscles and fat still attached. If possible pick up the cow's
eyes the day of the dissection, eyes are easier to cut when
they are fresh.

2. Before Beginning- Recorder Copy:
Part
Function
Actual Description from lab
10 total!
Recorder should fill in as dissection progresses!

3. Before Beginning: Digital Specialist copy
Video
Groups word summary! Do not go over or under! 1 2 3 4
Digital specialist should records GROUPS response after watching video!

5. STEP 1: EXAMINE EYE
Examine the outside of the eye. See how many parts of the eye
you can identify. You should be able to find the whites
(or sclera) and the clear
covering over the front of
the eye (the cornea). You
should also be able to
identify the fat and muscle
surronding the eye.
Add underlined parts to chart

6. Step 1: Continued
Remove pieces of fat and muscle from the back of the eye and find the thick optic nerve. We measured this diameter of your optic nerve in our blind spot lab. Watch video on Glaucoma.

7. STEP 2: FIRST INCISION Make the first incision where the sclera meets
the cornea. Cut
until the
aqueous humor
is released.

8. STEP 3: CORNEA Rotate the eye and cut around the cornea. Be
careful not to
cut too deep.
As the
cornea starts to
cut free, hold
the cornea in
the center and
make the last
cuts around it. Watch the Lasik eye surgery video to see how the cornea can be reshaped.

9. STEP 4: CORNEA Once you have removed the cornea, place it on
the board (or
cutting surface)
and cut it with
your scalpel or
razor.

10. STEP 5: IRIS
With the cornea removed, the next step is to pull out the iris. Place one finger in the center of the eye. Find the iris and pull it back. It should come out in one piece, notice the hole in the center, the pupil. Look at your lab groups iris’s. Everyone is unique and as individual as a fingerprint. Does anyone have any freckles on their iris?

11. STEP 6: SCLERA It can be a bit tricky to remove the lens with the
vitreous humor
attached. It works
best if you cut slits
in the sclera. Be
careful not to cut
the lens.

12. STEP 7: LENS After enough incisions have been made in the
sclera, you should
be able to remove
the lens.
Sometimes the
vitreous humor
will be removed
along with the
lens.

13. STEP 8: EXAMINE LENS Hold up the lens and look through
it. If the lens is
too slippery, pat
it dry and try
again. Check out the
cataract surgery video.

14. STEP 9: RETINA The thin, brownish tissue on the back of the
eye is the retina.
Find the spot
where the retina
is attached. The
shiny blue-green
material is the
tapetum.
Humans do not have this shiny layer.

15. STEP 10: OPTIC NERVE Find the spot where all the retina's nerves
collect. It is called
the blind spot.
This is where all
the nerves go out
the back of the
eye, forming the
optic nerve.

16. STEP 13: CLEAN-UP
Once the dissection is complete, properly dispose of the
remains. Please clean all tools and dissecting pan. Spray down your table.