Which of the following is the function of the iris of the mammalian eye?

The function of the iris of the mammalian eye is to regulate the amount of light entering the eye. The iris is the colored part of the eye surrounding the pupil, and it contains muscles that control the size of the pupil. These muscles can contract or expand, depending on the amount of light present. In bright light, the iris contracts and the pupil becomes smaller, which reduces the amount of light entering the eye. In dim light, the iris expands and the pupil becomes larger, which allows more light to enter the eye. This mechanism helps to protect the sensitive retina at the back of the eye from being overwhelmed by too much light, while still allowing sufficient light to pass through for clear vision.