8th Grade Cow Eye Dissection
|
||
|
8th Grade Cow Eye Dissection |
|
The Cross-Section
Functions
The Iris
The iris is the colored part of the eye. Just like an aperture on a camera, the iris controls how much light is let in through the pupil and into the eye. The dilator and sphincter muscles inside of the iris widen and narrow the pupil to control the amount of entering light.
The color of the iris comes from microscopic pigment cells called melanin. Irises can be different shades of many colors, including brown, blue, green, hazel, and others.
The iris divides the front of the eye from the back of the eye. These two areas are called the posterior and anterior chamber.
The Pupil
The pupil is the seemingly black hole in the center of the iris. It is the only place in which light can enter the eye. The general size of the pupil determines how much light is allowed to enter. The size of the pupil is controlled by the dilator and sphincter muscles of the iris. When there is an abundance of light, the iris’s muscles will contract around the pupil so that it becomes smaller and less light is capable of entering the eye. When a minimal amount of light is available, the iris’s muscles will expand the pupil so that it becomes larger and more light is capable of entering the eye.