Object Lessons on the Human Body / A Transcript of Lessons Given in the Primary Department of School No. 49, New York City

by Sarah F. Buckelew; Margaret W. Lewis

What is the colored ring called?—"The iris."

Of what use is the iris?—"It acts like a curtain to the eye; it lets in and keeps out light from the pupil."

Of what shape is the iris?—"Round like a ring."

Of what color is the iris?—"Sometimes blue, sometimes brown, sometimes gray."

Does the iris always appear the same in size?—"It does not: sometimes it looks large, sometimes small."

When is it the largest?—"When it rolls over the pupil to keep out the strong light."

When is it the smallest?—"When it rolls backward, to let light into the pupil."

When is the pupil the largest?—"When we are in the dark."

When is the pupil the smallest?—"When we are in a bright light."

What color is the eyeball?—"White."