The difference between a sheep eye and a human eye
Even though a sheep eye and a human eye are different, they do share a few similarities. Sheep cannot see color, but they do have better peripheral vision than humans do. Scientists are very interested in studying the eyes of sheep because their research has led them to believe they can discover many new things about vision in humans and how they can correct problems.
It is extremely difficult to compare the eyes and the vision of two different species. In the case of the sheep eye and the human eye, though, there are many differences. The human eye has a fovea in the retina where the vision cells are located. This allows people to have sharp, clear vision. There is no fovea in the eye of a sheep, which means they are unable to focus on a specific object as humans can.
The eyes of the sheep are located on the sides of the head which enables them to be able to have a better peripheral vision, and this means that they have better vision to the sides. The human eyes face forward and this gives them overlapping, binocular vision. The eyes of the sheep are farther back on the top of their heads so that they have the ability to scan areas that are close by while they are grazing. This is also something that humans are unable to do.
Humans have a narrower field of vision than sheep, but they do have a greater field of depth perception than sheep. But this is not regarded as a major fault of the sheep eye because sheep not need depth perception in order to see grass in the field. For them the peripheral vision is more important because it enables them to see predators and this gives them time to escape.
More differences between the sheep eye and the human eye
- The human eye has a circular shaped pupil, but the pupil in the sheep eye is oval in shape.
- In the eye of the sheep there is a layer of tissues called the tapectum lucidum and this causes light to reflect off the eyes. This tissue is not present in the human eye.
- Sheep have eyes on the sides of their heads, but human eyes face forward.
- The human eye has depth perception, but the sheep eye does not.
- In the human eye there are six muscles to allow movement, but in the sheep eye there are only four.