THE HUMAN EYE
Biology 12
Nervous
System
EYE
The eye is an
extension of the
brain. It helps us
take in light
information from
our
surroundings.
https://www.yo
utube.com/watc
h?v=gvozcv8pS3
c
EYE BRAIN
PROXIMITY
 Can you see:
 The optic nerve bundle?
 Spinal cord?
WHAT ARE THE PARTS OF THE EYE?
CORNEA
Transparent membrane that covers iris and pupil.
Focuses light on the retina.
PUPIL, IRIS, SCLERA
Pupil – Black hole in iris where the light enters the eye.
Iris - Colored part of the eye that controls the size of the pupil.
Sclera - “whites” of the eye that forms outer covering, providing
support and attachment for muscles.
AQUEOUS HUMOR,
CILIARY MUSCLE, LENS
Aqueous Humor - Nutritious fluid between the iris and the
cornea. As we age, it breaks down and we begin to see “floaters”
Ciliary Muscles - Produces aqueous humor and controls lens
shape.
Lens - Bends light rays to the back of the eye (retina). Allows us
to see objects near and far.
RETINA
 Full of light receptors
which are sensitive to:
 Cones - Colour
 Rods- Light levels
 Massive blood supply is
also needed
 Internal membrane
Blind Spot - site of
optic nerve
connection
VITREOUS HUMOR, BLIND SPOT,
OPTIC NERVE
Vitreous Humor -Transparent
jelly-like fluid that fills the
eye and refracts light
Optic Nerve - Sends messages
picked up by retina to the
brain
Blind Spot - Area where optic
nerve attaches. No retina is
located there so information
cannot be picked up. No rod
or cone cells.
CHOROID LAYER, TAPETUM
LUCIDUM
Choroid Layer - Lies between the sclera and the retina it provides
the blood supply to the eye.
Tapetum Lucidum - Iridescent film under the retina that provides
animals with “night vision”
CROSS
SECTION
You must know:
1. Lens
2. Cornea
3. Aqueous humor
4. Pupil
5. Iris
6. Ciliary Muscle
7. Sclera
8. Vitreous Humor
9. Retina
10. Blind Spot
11. Choroid Layer
12. Optic Nerve
13. Tapetum Lucidum
Choroid Layer
Taptem lucidum
Sclera
Blind
Spot
Ciliary
VIDEO & EXTRA LINKS
 https://www.youtube.com/watch?v=cTZl2qnzifc
 https://www.youtube.com/watch?v=_5dEO -LRVg&feature=youtu.be
 http://interactivehuman.blogspot.ca/2008/05/eye -animationlearn-how -you-eye-works.html
 http://www.yorku.ca/eye/eye1 .htm