Sheep Eye Dissection Analysis

In class, we dissected a sheep's eye to better understand the structure and physiology of the eye. First we cut all the fatty tissue off of the eye and there was a significant amount of it. This is because it is the cushion for the eye while the extrinsic muscles move the eye. The cornea was the bluish part while the optic nerve was behind that. Then we cut through the sclera which is very tough and makes up the 'whites' of the eye. When we cut it open we saw the retina, vitreous humor and choroid, which was behind the retina. The retina contains the photoreceptors for vision while the vitreous humor is a clear gel-like substance and the choroid which brings blood, nourishment, and oxygen to the eye. The tapetum lucidum is a part of animal eyes that is not a part of human eyes as it helps with night vision as it reflects light. The ciliary bodies surrounding the lens encircle the lens and controls lens shape while the lens focuses light on the retina. One condition of the lens is cataracts which is when the lens becomes cloudy and the amount of light reaching the retina is lessened or prevented. When the lens is removed, it reveals the iris and pupil; between the iris and cornea is aqueous humor which also helps maintain the shape of the eye. A condition of the aqueous humor is glaucoma where fluid pressure becomes too high and it damages the eye. Like with the tapetum lucidum, a sheep's eye is different from a human's also because the pupil of a sheep's eye is more oval-shaped compared to that of a human's. From this lab, I could clearly see the different structures and functions of the eye and how significant the relationship between the two is, such as with the shape of the pupil and retina.