Page 95 - Science Course 3 (Book 2)

Mo10-L6c: How Does the Human Eye Work?

Mo10–L6c How Does the Human Eye Work?

KEY CONCEPTS:
1. How does the human eye enable a person to see?

Vocabulary A-Z

Let us learn some vocabulary Pupil Iris Retina

Cornea
Lens

Ciliary Muscle
Optic nerve

The eye is made of a number of parts that have
different functions.

Lens - transparent structure that can change shape
and help form an image on the retina.

Iris - relaxes and contract to control the amount of
light that enters the eye. The iris is the colored part
cornea of the eye.

a convex lens made of transparent tissue located
on the outside of the eye. Cornea - transparent tissue layer that changes the
direction of light rays as they enter the eye. The
pupil cornea is a convex lens made of transparent tissue
located on the outside of the eye.
an opening into the interior of the eye at the center
of this iris.
Pupil - the opening into the eye through which light
enters. The pupil is the dark opening into the interior
iris
of the eye.
the colored part of the eye.

Ciliary Muscle - contract and relax to control the
retina shape of the lens.

a layer of special light-sensitive cells in the back of
the eye. Optic nerve - carries signal from the retina to the
brain.

Retina - thin layer of
Let’s Begin tissue that contains
light-sensitive cells.

Light and the Human Eye

To see an object, light waves from an object travel
through two convex lenses in the eye—the cornea
and the lens.

87