pupil (P) [pu´pil]
the opening in the center of the iris through which light enters the eye; see also Plate 17.
Argyll Robertson pupil one that is miotic and responds to accommodation effort, but not to light.
fixed pupil a pupil that does not react either to light or on convergence, or in accommodation.
Hutchinson's pupil one that is dilated while the other is not.
a usually unilateral condition of the eye in which the affected pupil is larger than the other, responds to accommodation and convergence in a slow, delayed fashion, and reacts to light only after prolonged exposure to dark or light; see also adie's syndrome
. Called also Adie's pupil
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
pupil (pu'pil) [L. pupilla, little doll (the reflection in the pupil)]
The contractile opening at the center of the iris of the eye. It is constricted when exposed to strong light and when the focus is on a near object; is dilated in the dark and when the focus is on a distant object. Average diameter is 4 to 5 mm. The pupils should be equal. See: pupilla
Constriction of the pupil occurs, for example, in bright light and after exposure to drugs such as morphine, pilocarpine, physostigmine, eserine, and other miotics.
Dilation of the pupil is most often observed after treatment with mydriatic drugs (such as atropine, scopolamine, or homatropine), but may also be caused by paralysis of cranial nerve III, intracranial masses or trauma, sympathetic nervous system stimulation, and other pupillary stimuli.
Adie pupil See: Adie, William John
Argyll Robertson pupil See: Argyll Robertson pupil
A pupil made by iridectomy when the normal pupil is occluded.
Rapid dilatation of a pupil, alternating with contraction.
Dilatation of the pupil owing to psychic stimulus.
A pupil that is narrow and slitlike.
Dilated pupils found in agricultural workers who are exposed to dust from jimsonweed. The dust contains stramonium, a mydriatic.
A pupil that does not react to stimuli.
Gunn pupil See: Gunn, Robert Marcus
A pupil with an artificial coloboma at the pupillary margin.
luetic pupilArgyll Robertson pupil.
Marcus Gunn pupil See: Gunn, Robert Marcus
A pupil of minute size; one excessively constricted; seen after use of miotics, in opium poisoning, and in certain brain disorders.
Robertson pupil See: Argyll Robertson pupil
stiff pupilArgyll Robertson pupil.
tonic pupilAdie pupil
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