The Brain and Eye

To focus on a near object

• the ciliary muscles contract

• the suspensory ligaments loosen

• the ciliary muscles relax

• the suspensory ligaments are pulled tight

To focus on a distant object:

• the ciliary muscles relax

• the ciliary muscles contract

• the suspensory ligaments are pulled tight

• the suspensory ligaments loosen

The lens is then thicker and refracts light rays strongly,

• to focus on a near object

• to focus on a distant object

What does the optic nerve do?

• transmits electrical impulses from retina to brain

• receives light and sends it to brain

• helps the eye focus

• transmits light rays to retina

What does the iris do?

• transmits light rays to retina

• sends messages to the brain

• helps the eye focus

• regulates how much light enters the eye

What does the sclera do?

• protects the eye

• allows light to enter eye

• helps the eye focus

• transmits light rays to retina

Myopia is a common eye defect in which

• the image focuses on the retina

• the image focuses before it reaches the retina

• the image focuses after is reaches the retina

Myopia can be corrected by using a concave lens.

• This shortens the focal length of the defective lens

• This increases the focal length of the defective lens.

The lens of your eye is convex. Because of this, what happens to light as it passes through the lens?

• The light is absorbed.

• The light is reflected

• The light is refracted

The term accommodation refers to

• the ability of the eye to focus on near and distant objects

• the ability of the eye to see in colour

• the ability of the eye to change the amount of light that enters the eye