The Eye Flashcards
1
Q
What is the eye?
A
- hollow ball filled with fluid
- allows us to see by focusing light on photoreceptors at the back
2
Q
What are the layers of the eye?
A
- external: sclera and cornea
- intermediate: choroid, iris, pupil, ciliary muscles
- internal: retina
3
Q
Describe the sclera
A
Tough, white outer covering of eye
4
Q
Describe the cornea
A
Transparent area of sclera at front of eye (light enters here)
5
Q
Describe the choroid
A
- intermediate layer
- absorbs stray light waves
- contains blood vessels that supply eye with nutrients and oxygen
6
Q
Describe the iris
A
Made of muscle that contracts or relaxes to allow different amounts of light in (adaptation)
7
Q
Describe the pupil
A
The “hole” in the centre of the eye where light gets through
8
Q
Describe the coliseum muscle/lens
A
Ciliary muscle adjusts lens to help focus light on retina
9
Q
Describe the retina
A
- internal layer of the eye
- contains photoreceptors:
- rods: sensitive to light intensity (brightness)
- cones: sensitive to different colors (concentrated in fovea centralis)
- optic nerve: collects this information and sends it to the brain
10
Q
Describe the aqueous humour
A
- fluid in anterior (front) chamber of eye
- maintains cornea shape
- provides oxygen and nutrients to lens and cornea
11
Q
Describe the vitreous humour
A
- fluid in posterior (rear) chamber
- helps maintain shape of eyeball
