Mydriasis

n.

1.

(Physiol. & Med.) A long-continued or excessive dilatation of the pupil of the eye.

Noun

1.

mydriasis - reflex pupillary dilation as a muscle pulls the iris outward; occurs in response to a decrease in light or certain drugs

dilatation, dilation, inborn reflex, innate reflex, instinctive reflex, physiological reaction, reflex, unconditioned reflex