Reflex contraction of the sphincter muscle of the iris in response to a bright light (or certain drugs) causing the pupil to become smaller

• Contraction of the pupil - Miss Yo
• An acute infectious disease occurring in epidemic form and featuring paroxysms of pain (usually in the chest)
• Eye ailment
• Contraction of the pupil — Miss Yo (anag)
• Excessive constriction of the pupils

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Myosis \My*o"sis\, n. [NL., fr. Gr. ? to close the eyes or lips.] (Med.) Long-continued contraction of the pupil of the eye.

Wiktionary Word definitions in Wiktionary
n. (alternative spelling of miosis English)

WordNet Word definitions in WordNet
n. an acute infectious disease occurring in epidemic form and featuring paroxysms of pain (usually in the chest) [syn: epidemic pleurodynia , epidemic myalgia , diaphragmatic pleurisy , Bornholm disease ] reflex contraction of the sphincter muscle of the ...