Hutchinson's pupil is a medical sign that was first described in 1872 by Sir Jonathan Hutchinson. It is seen in conditions such as meningitis, which is an inflammation of the protective layers of the brain, and in certain types of eye inflammation.
The sign is named after Hutchinson due to his description of it in his book On Diseases of the Eye, in which he wrote that the pupil of the eye affected appears to be slightly larger than normal and does not respond to light. This is a result of the spasm of the iris, which is the colored part of the eye that surrounds the pupil and controls the size of the pupil.
In addition to meningitis and certain eye inflammations, Hutchinson's pupil can also be seen in other medical conditions such as brain tumors, hydrocephalus, and certain types of stroke. It is important to note that Hutchinson's pupil is not a symptom of any medical condition, but rather a sign of it. As such, the presence of Hutchinson's pupil should be evaluated by a doctor in order to determine the underlying cause.