Final answer:
Visual adaptation is the ability of the eyes to adjust to changes in illumination. It involves changes in the size of the pupil and sensitivity of the photoreceptor cells in the retina.
Step-by-step explanation:
Visual adaptation is the ability of the eyes to adjust to changes in the surrounding environment, particularly in terms of illumination. It allows us to see clearly in different lighting conditions. For example, when moving from a dark room to a bright one, our eyes quickly adapt to the increased amount of light. This is achieved through changes in the size of the pupil and the sensitivity of the photoreceptor cells in the retina.
One of the key components of visual adaptation is the adjustment of the iris, which controls the size of the pupil. In bright environments, the iris contracts and makes the pupil smaller to reduce the amount of incoming light. Conversely, in dim environments, the iris expands and makes the pupil larger to allow more light to enter the eye.
Visual adaptation to changes in illumination is crucial for our ability to perceive visual information accurately. Without adaptation, sudden changes in brightness would make it difficult for us to see clearly and could potentially damage the eyes.