In the visual system,the major purpose of the iris of the eye is to
A)stimulate the sclera into refracting light.
B)control the pupil size.
C)change the wavelength of light entering the eye.
D)produce rods and cones.

Question

Quizplus · Accepted Answer

The iris is a circular muscle that surrounds the pupil and can contract or relax to control the amount of light entering the eye. This is accomplished by changing the size of the pupil. Therefore, the major purpose of the iris is to control pupil size. A is incorrect because the sclera is the white outer layer of the eye and does not refract light. C is incorrect because the wavelength of light is not changed by the iris. D is incorrect because rods and cones are photoreceptor cells located in the retina, not the iris.

In the Visual System,the Major Purpose of the Iris of the Eye