dilator pupillae muscle

(redirected from dilator iridis)

di·la·tor pu·pil·lae mus·cle

intrinsic so-called muscle of eyeball; radially disposed layer of muscular processes of the myoepithelial cells that form the epithelium of the posterior surface of the iris, which extends from the pupillary to the ciliary margin; sympathetic stimulation causes contraction, which slowly dilates the pupil to allow more light to reach the retina.


a structure (muscle) that dilates, or an instrument used to dilate.

dilator pupillae muscle
dilator muscle of the pupil.