#5036 Daily Warm-Ups: Nonfiction Reading
68
©Teacher Created Resources
Warm-Up
Check Your Understanding
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4
Name ______________________________________________
1.
If
constricts means to get smaller, what is the meaning of
dilate?
a.
to get larger
c. to get much smaller
b.
to open
d. to not see
2.
What are the floating objects you see in your eye if you look upwards and sideways?
a. dust
c. water
b.
microscopic particles
d. smog
3.
What is the main idea of the passage?
a. The human eye is a remarkable organ of sight.
b. The retina is sensitive to light.
c. Blinking is harmful to the eye.
d. Eye muscles move very often in one day.
4.
What carries messages from the eye to the brain?
a. the lens
c.
nerves
b. the retina
d. the cornea
Light enters the eye through the cornea at
your outer eye.
The pupil either dilates
or constricts, depending on the amount of
available light. The lens keeps the image in
focus. The retina at the back of your eyes
contains about 125 million rods and 7 million
cones. These are nerve cells that are sensitive
to light. The retina is about as thick as a
very thin sheet of paper.
The eye has special
cells sensitive to red, green, and blue light.
Your brain can put different amounts of these
colored lights together in order to see about
ten million different shades of color. The lens
of your eye is about the size of a small bean
when you are a child, but it will grow larger
as you age. Your lens is made up of layers of
cells wrapped like an onion.
The nerves in
your eyes carry more information to your
brain than most computers could handle.
If you look upwards and sideways toward a
light-colored object, you may see tiny floating
objects swimming in your eyes. These
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