COMPARING THE EYE AND A CAMERA
Name:______________________
Class: _____________
What is an “eye” made up of?
The human eye is a transparent window. At the front of the eye is a structure
called the cornea. This lens-like structure focuses the light reaching it. The hole
in the center of the iris is called the pupil and the coloured part of the eye is the
iris. The retina is very important as it is the inner lining of the eyeball. Receptor
cells called rods and cones make up the retina. Black and white vision is seen
by the rods and color vision is received by the cones. These messages are then
sent to the brain via the optic nerve, which runs from the eye to the brain.
How do eyes work?
The individual components of the eye work in a manner similar to a camera.
Each part plays a vital role in providing clear vision. A human eye is like a
camera, with the cornea acting as the camera lens cover. As the eye’s main
focusing element, the cornea takes widely diverging rays of light and bends them through the pupil, the dark,
round opening in the center of the colored iris. The iris and pupil act like the aperture of a camera. Next in line
is the lens which acts like the lens in a camera, helping to focus light to the back of the eye.
The very back of the eye is lined with a layer called the retina which is similar to the film in a camera. The
retina is a membrane containing receptor nerve cells that line the inside back wall of the eye. The receptor
cells (rods and cones) of the retina change the light rays into electrical impulses and send them through the
optic nerve to the brain where an image is perceived.
The human eye is remarkable. It accommodates to changing lighting conditions and focuses light rays
originating from various distances from the eye. When all of the components of the eye function properly, light
is converted to impulses and conveyed to the brain where an image is perceived.
Complete the following chart:
Question
What structure(s)
gather light?
What structure(s)
control the amount of
light entering?
What structure(s)
“focus” an image?
What structure(s)
produce the overall
image?
Human Eye
Camera
ONCE YOU’RE DONE THE TABLE:
1) Using your textbook (page 211 and 218), label the parts of the camera and the eye on the diagrams below.
2) B`elow each part of the camera and eye, include its FUNCTION ***
3) Create a Venn Diagram to compare the functions of the parts of the camera and the eye
What is a “Venn Diagram” ?
An illustration that uses
overlapping and non-overlapping
circles to show the similarities and
differences between objects.
Differences
Similarities
Differences
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Terms to Include:
1. Optic Nerve
2. Ciliary muscles
3. Cornea
4. Iris
5. Retina
6. Pupil
7. Lens
8. Sclera
Terms to Include:
1. Film
2. Aperture
3. Lens
4. Lens cap
5. Shutter