Mydriasis is the medical term for the dilation of the pupils in the eyes. This condition can occur in response to low light conditions, allowing more light to enter the eye, or as a reaction to certain medications, drugs, or medical conditions. In some cases, mydriasis can be a sign of an underlying health issue, such as brain injury or glaucoma. It is important to monitor pupil size and reactivity, as abnormal changes may require medical evaluation to determine the cause and appropriate treatment.