Question

a nurse is testing a clients pupillary reaction to light, noting that the pupil constricts when shining light obliquely into it. the nurse understands that muscles in which of the following structures adjust to control the amount of light entering the eye through the aperture of the pupil?
lens
iris
optic disc
retina

Explanation:

The iris contains muscles that control pupil size to regulate light - entry. Other structures have different functions.

Answer:

B. Iris