Cow Eye Virtual Dissection

1. Cut the fat around the eye

cut fat

2. Puncture the cornea with scissors or a scalpel, aqueous liquid should leak out. The cornea is pinned here.

cornea

 

3. Cut the eye into a front and a back half.

cut eye

4. Open the eye. The gelatinous fluid inside is the vitreous humor, the lens sits within this liquid.

vitreous humor

5. Separate the parts of the eye. The lens is the hard, sphere-shaped structure sitting on (or in) the vitreous humor.

eye opened

lens

6. On the back of the eye, the thin layer of cells of the retina can be seen here, it is very thin and easy to pull away. The spot where they remain attached is the optic disk, which connects the retina to the optic nerve.

retina

7. The tapetum is clearly visible with the retina removed. It is blue and shiney and will reflect light. This helps a cow to see in the dark. Notice on this photo, you can see the optic disk, the spot where the retina is still attached.

tapetum

 

8. This student has carefully removed the iris, which can be difficult to get out in one piece. The hole in the center of the iris is the pupil.

iris

 

9. These eye parts are separated so that you can clearly see the main structures.

eye parts

 

10. The optic nerve can be seen on the back side of the eye, the nerve is usually buried within the fat, so it takes some work to find it and expose it.

nerve