Sheep Eye Dissection Analysis

In the sheep eye dissection, we went through and examined the different parts of the eye. On first glance, we noticed the cornea, fatty tissue, optic nerve, sclera and extrinsic muscles. The cornea is the first layer of the eye and shields the eye from potential harm. The fatty tissue lines the eye and helps cushion it. The optic nerve is located in the back of the eye and transfers information from the retina all the way to the brain. The sclera is the white of the eye and also protects the eye from injury. The extrinsic muscles help the eye move in different directions.

Then, we cut the eye in half and examined the inside parts. The very top of the photo shows the part of the eye that contains the retina and choroid. The retina is a very thin layer that lines the back of the eye and receives light which turns into signals and forwards them to the brain for visual recognition. It is attached to the choroid at the blind spot. At this very spot, all the nerve fibers leave the retina and come together to form the optic nerve which should be directly behind this spot. The choroid provides nourishment to the eye and is pretty dark in color and thin. Also, because of its dark color it absorbs light so it is not reflected around within the eye. In the sheep eyeball, it contains the tapetum lucidum which reflects light onto the retina. It helps animals with night vision since it can reflect light even with low intensities and is often shiny with a bluish color.
The middle part shows the lens, ciliary body, suspensory ligaments, and the vitreous humor. The lens is typically transparent and should be convex shaped as well as somewhat elastic. It is held in place by the suspensory ligaments.These ligaments eventually join with the smooth muscle which contain ciliary body. Ciliary body helps produce aqueous humor and also contains muscles that help change the shape of the lens as we view different things. The vitreous as well as aqueous humor help maintain the shape of the eye.
In the bottom, we can see the pupil and iris. The pupil is the hole in the eye and helps regulate the amount of light that enters into the eye. It gets bigger when there is less light and gets smaller when there is too much light. The iris is on the backside of the pupil and controls the size of the pupil and also gives us our eye color.