Long-continued contraction of the pupil of the eye.

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.. Myosis can be physiological (natural adaptation of the eye to intense light), pathological (paralysis of the muscle which dialates and iris) or pharmacodynamic (effect of a drug, e.g pilocarpine). ( miosis, n.f)

an acute infectious disease occurring in epidemic form and featuring paroxysms of pain (usually in the chest)