1. Biology: Electrical Signals

2. Biology: Electrical Signals

3. Biology: Electrical Signals
The iris reflex
Biology:
Electrical Signals

4. Biology: Electrical Signals
Inside the eye
Biology:
Electrical Signals
cornea
protects eye surface and focuses light rays
suspensory ligaments
retina
senses light
hold lens in place
lens
focuses light on retina
iris
regulates amount of light entering eye
optic nerve
ciliary muscles
transmits impulses to the brain
change shape of the lens

5. What is binocular vision?
Biology:
Electrical Signals
Animals with binocular vision have eyes close together. This provides an overlapping field of view and enhanced depth perception.
Predators tend to have binocular vision because they need to judge distances and anticipate the movement of prey.
no field of vision
monocular field of vision
binocular field of vision

6. What is monocular vision?
Biology:
Electrical Signals
Animals with monocular vision have eyes spaced apart, providing a very wide field of view.
Prey animals tend to have monocular vision because they need to see predators approaching from any direction.
no field of vision
monocular field of vision
Animals like the horse have a combination of monocular and binocular vision.
binocular field of vision

7. Biology: Electrical Signals
Accommodation
Biology:
Electrical Signals
Teacher notes
This interactive simulation illustrates how the eye focuses on objects at different distances. Suitable prompts could include:
Start: How can you tell the image this eye can see is in focus?
Distant objects: Why isn't the STOP sign in focus?
Close objects: Why isn’t the paper in focus

8. Biology: Electrical Signals
Correcting sight
Biology:
Electrical Signals
Teacher notes
It could be worth asking students the difference between concave or convex lenses.

9. What is colour blindness?
Biology:
Electrical Signals
Colour blindness (dichromatism) means that a person has difficulty distinguishing between red and green.
Colour blindness is caused by a lack of receptors in the retina and affects about 7% of men and 1% of women.
What can you see in the circle?
If you have normal vision you can see an eye in the image. If you are colour blind you can only see either red or orange spots.

10. Biology: Electrical Signals
Parts of the eye
Biology:
Electrical Signals