What is an indication of an abnormal pupillary response?

An indication of an abnormal pupillary response is when the pupils remain unchanged regardless of light exposure. In healthy individuals, the pupils should constrict in response to bright light (to protect the retina and limit excess light exposure) and dilate in darker environments (to allow more light into the eye for better vision).

If the pupils do not react at all to changes in light intensity, it suggests a potential neurological issue or damage to the pathways involved in the pupillary light reflex. This could involve problems with the retina, optic nerve, brainstem, or the muscles that control pupil size.

In contrast, other options describe normal pupillary responses: constriction when light is shone indicates a healthy response, and constriction in dark environments signifies a proper dilation process followed by constriction when exposed to light. A response to touch usually reflects the reflexive action of pupil accommodation rather than a direct response to light. Therefore, unchanged pupils in response to light are a clear indicator of an abnormality.