Answer: The Iris
Step-by-step explanation:
The iris is the colored ring of muscle tissue located in the front of the eye, surrounding the pupil. The pupil is the opening in the center of the iris that allows light to enter the eye.
The iris regulates the amount of light that enters the eye by controlling the size of the pupil. When the iris contracts, the size of the pupil decreases, allowing less light to enter the eye. This is known as "miosis" and is the body's response to bright light. On the other hand, when the iris relaxes, the size of the pupil increases, allowing more light to enter the eye. This is known as "mydriasis" and is the body's response to dim light.
In summary, the iris, which is the colored ring of muscle tissue in the front of the eye, controls the amount of light that enters the eye by adjusting the size of the pupil, the opening in the center of the iris.