Definition of miosis in English:



(also myosis)
  • Excessive constriction of the pupil of the eye.

    ‘Symptoms include nasal congestion, ptosis of one eyelid, miosis, and conjunctional hyperemia.’
    • ‘Oral pilocarpine is contraindicated in patients with uncontrolled asthma and in patients in whom miosis is undesirable, such as patients with acute iritis or narrow angle (angle closure) glaucoma.’
    • ‘After inhalation of vapour, respiratory symptoms, dimming of vision, and miosis are generally the first clinical features to appear.’
    • ‘Although miosis was the most common symptom, severely poisoned patients developed CNS symptoms and cardiomyopathy.’
    • ‘A stimulant action on the parasympathetic portion of the oculomotor nucleus (third cranial nerve) is responsible for pupillary miosis.’



/mīˈōsəs/ /maɪˈoʊsəs/


Early 19th century from Greek muein ‘shut the eyes’+ -osis.