The term "eye shutter" is not a standard or widely recognized term in ophthalmology or visual science. Based on context, it likely refers to the iris, which functions similarly to a camera shutter by controlling the amount of light entering the eye.
Here's a breakdown:
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The Iris: The iris is the colored part of the eye, a muscular diaphragm that surrounds the pupil.
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Pupil Control: The iris expands or contracts, changing the size of the pupil. This regulates the amount of light that reaches the retina, the light-sensitive tissue at the back of the eye.
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Analogy to a Camera Shutter: Just as a camera shutter opens and closes to control the exposure of the film or sensor to light, the iris adjusts the pupil size to regulate the amount of light entering the eye. This adjustment is crucial for clear vision in varying light conditions. In bright light, the iris contracts, making the pupil smaller to reduce the amount of light entering. In dim light, the iris dilates, making the pupil larger to allow more light in.
Therefore, if someone refers to the "eye shutter," they are likely referring to the iris and its function of controlling light entry through the pupil. It's an analogy borrowed from camera technology to explain how the eye adapts to different light levels.
