What reaction should an infant have when a light is shone into their visual field during a vision screening?

When a light is shone into an infant's visual field during a vision screening, the expected reaction is for the infant to close their eyes. This reflects a protective reflex response to bright light, as the eyes are sensitive and not fully developed at this stage.

Infants typically exhibit a basic reflexive behavior when exposed to bright lights, which is their way of protecting their eyes from sources that may be perceived as harsh or uncomfortable. This response is part of their instinctual behavior rather than a conscious action, and it demonstrates that the infant has a certain level of visual awareness and sensory processing.

In contrast, other responses may indicate different developmental issues or sensory processing capabilities, but the reflex of closing the eyes is what is expected in this situation.