The primary purpose of the iris is to control the amount of light that enters the eye.
The iris, along with the pupil, acts like the aperture of a camera. By adjusting the size of the pupil, the iris regulates the intensity of light reaching the retina, optimizing vision in various lighting conditions.
Here's a breakdown of how it works:
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In Bright Light: The iris constricts, making the pupil smaller. This reduces the amount of light entering the eye, preventing overstimulation of the retina and protecting it from damage.
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In Dim Light: The iris dilates, making the pupil larger. This allows more light to enter the eye, enhancing visibility in low-light conditions.
Essentially, the iris ensures that the retina receives the optimal amount of light needed for clear vision without being overwhelmed or understimulated. This contributes significantly to our ability to see comfortably and effectively in a wide range of environments.
