1. Supplies:
Print: 10
Demo:

2. Warm-Up Exercise
A mirror reflects an object at a distance of 10 cm with an image that is 18 cm away.
Where is the focus?
What is the radius of the circle?
An object is 20 cm tall and is magnified to 57 cm tall. What is the magnification?
Solve the following:
4x x10-3
BONUS :Is there
something “more” to
this scene? 

3. Demos Touch fingers together with eyes closed. Ensure elbows are bent
Stand on one foot with and without eyes closed
The Blind man, healed twice! Mark 8
How babies’ eyes form in the mother’s womb

4. Optics Tomorrow: LESSON: Classwork QUIZ, Ray Diagrams
Drawing and labeling Ray diagrams
Refraction
Concepts of mirrors, SALT
Magnification and focal lengths
LESSON:
The Eye
Eye tests
Classwork

5. An ophthalmologist is a physician who specializes in eye care

6. Dominant Eye Test
Extend both hands forward of your body and place the hands together making a small triangle (approximately 1/2 to 3/4 inch per side) between your thumbs and the first knuckle.
With both eyes open, look through the triangle and center something such as a doorknob or the bullseye of a target in the triangle.
Close your left eye.
If the object remains in view, you are right eye dominant. If your hands appear to move off the object and move to the left, then you are left eye dominant.

7. The Amsler Grid (Tests for age-related macular degeneration – AMD)
Stand 12 inches to 14 inches away (generally a comfortable reading distance).
If you wear glasses, keep them on.
Cover one eye and look at the dot in the center of the grid.
Watch for:
Distortions or breaks in the lines of the grid.
Disappearing of lines
Blurring or grey areas
Distortion or wavy lines
Holes or spots in any areas of the grid

8. The Snellen Chart An eye chart used to measure visual acuity
Named after the Dutch ophthalmologist Herman Snellen (1862)
Uses combinations of 10 letters
(Ensure the top letter is 88.7 mm tall)
Viewers read from 20 feet away

9. Reading a Snellen Chart
20/20
Standard acuity.
20/40
You can read at 40 feet what someone can read at 20 feet etc.
20/200
Inability to read the top letter from 20 feet is considered “legally blind”

10. The Human Eye

11. Cornea The outer surface of your eye Transparent layer of tissue
Contributes 65-75% of the eye’s total focusing power

12. Pupil a hole that allows light to pass through the eye
Enlarges in the dark or when stimulated

13. Iris It is created by the circular band of muscle.
Determines your eye color
The iris controls the size of the pupil

14. Retina
It is the inner lining in the back of the eye and is a projection screen for the light entering your eye

15. Detecting Light Photoreceptors
Enable you to see. This is how the light rays are absorbed.
Rod Cells
Help us detect shape and movement in the dark.
Cone Cells
Detect colour

16. Do Eyes Change Shape? What type of lens is in front of your eye?
This convex lens is attached to a tiny circle of muscles that can adjust its shape
Why do aged people lose their vision?

17. Laser Eye Surgery Two main types of corrective eye surgery: PRK
Uses a precise laser to reshape the cornea
LASIK
Cuts the cornea and inserts a corrective lens under the flap

18. Finding your Blind Spot
A O X
Your face should be very close to the screen.
Cover right eye and focus the left eye on the X.
Now slowly move away /toward from the screen.
The O will disappear, while the A which is further to the left is still visible.
As you move further away, the O will reappear. (Observe that you do not see a hole. Instead of the O you see a uniform grey background.
The "hole" is filled in by your brain. Make sure there is not a glare on the screen as it will obscure the whole vision.)

19. Blind spot
Place where the optic nerve attaches to the retina
Optic nerve
connects your eye to the brain

20. Vision Problems Far-sighted Near-sighted Astigmatism
can see distant objects but not things close to them
Near-sighted
can see objects close to them but not far away
Astigmatism
eye is unable to see a sharp image
irregular shape of cornea

21. Color Blind Test What do you see?

22. Color Blind Test What do you see?

23. Color Blind Test What do you see?

24. Color Blind Test What do you see?

25. Color Blind Test You should see one or more pictures at the right 

26. Color Blind Test You should see one or more pictures at the right 

27. Color Blind Test What do you see?

28. Color Blind Test What do you see?

29. Colour and Vision
Most people who are legally blind are able to see some light
Colour blindness
The ability to only see shades of grey.
It occurs in 1 in 40,000 people.
The ability to see some colour but not others.

30. Review

31. Class Work
Pg. 481 #1,5,7,8,12,14