The iris is the colored part of the eye that surrounds the pupil. It functions like the aperture of a camera, controlling the amount of light that enters the eye. This is achieved through the contraction and expansion of its muscles, which adjust the size of the pupil. In bright conditions, the muscles contract, causing the pupil to constrict and reduce the amount of light entering the eye, thus protecting the retina from excessive light. In low light conditions, the muscles relax, allowing the pupil to dilate and allow more light to enter, enhancing the eye's ability to see in darkness. Therefore, the primary function of the iris is to regulate the amount of light entering the eye and optimize vision based on lighting conditions.
This mind map was published on 16 November 2023 and has been viewed 76 times.