1. VISION

2. LIGHT Electromagnetic energy described in wavelengths Electromagnetic energy described in wavelengths Main colors of the spectrum: ROYGBIV Main colors of the spectrum: ROYGBIV

5. PUPIL Determines amount of light let into eye Determines amount of light let into eye

7. LENS Focuses light rays onto the retina. Focuses light rays onto the retina. Adjusts to the distance of objects by changing its thickness (squint) Adjusts to the distance of objects by changing its thickness (squint)

9. RETINA Nerve layer that lines the back of the eye. Nerve layer that lines the back of the eye. Contains rods, cones, & neurons (photoreceptors) that process visual stimuli Contains rods, cones, & neurons (photoreceptors) that process visual stimuli Macula -- a small area in the retina - allows us to see fine details clearly. Macula -- a small area in the retina - allows us to see fine details clearly.

10. BLIND SPOT Part of retina that contains no photoreceptors Part of retina that contains no photoreceptors Located where Optic Nerve leaves the eye Located where Optic Nerve leaves the eye

11. CORNEA The clear front window of the eye. The cornea transmits and focuses light into the eye. The clear front window of the eye. The cornea transmits and focuses light into the eye.

13. IRIS The colored part of the eye. The iris helps regulate the amount of light that enters the eye. The colored part of the eye. The iris helps regulate the amount of light that enters the eye.

15. Vitreous -- the clear, jelly-like substance that fills the middle of the eye. Vitreous -- the clear, jelly-like substance that fills the middle of the eye.

16. OPTIC NERVE Connects the eye to the brain Connects the eye to the brain Carries the impulses formed by the retina to the brain, which interprets them as images. Carries the impulses formed by the retina to the brain, which interprets them as images.

18. RODS & CONES Rods - - night vision; black & white, light & dark Rods - - night vision; black & white, light & dark  95% of photoreceptors are rods  Rods - long + narrow

19. RODS & CONES Cones Cones  Responsible for color vision  About 5% of photoreceptors  Rods - thick + tapered  3 Types:  Red, Green/Yellow, Blue/Violet

20. COLOR BLINDNESS Partially or totally unable to distinguish color Partially or totally unable to distinguish color

24. COLOR BLINDNESS People who see all colors called trichromats (from the Greek term meaning “three colors” People who see all colors called trichromats (from the Greek term meaning “three colors” Smaller number of people see only two colors = dichromats Smaller number of people see only two colors = dichromats

25. COLOR BLINDNESS Monchromats -- See the world in only black and white. Occurs in about 1 in every 100,000 men. Monchromats -- See the world in only black and white. Occurs in about 1 in every 100,000 men.

26. COLOR VISION Color Circle – light spectrum is bent in a circle – colors across from one another are complimentary Color Circle – light spectrum is bent in a circle – colors across from one another are complimentary

27. COLOR VISION Afterimage = Afterimage =  visual sensation that occurs after original stimulus has been removed  Is seen in the complimentary color

28. -Stare at the eye of the red parrot while you count slowly to 20, then look immediately at one spot in the empty bird cage. The faint, ghostly image of the blue green bird will appear in the cage. -Try the same thing with the green cardinal. A faint magenta bird will appear in the cage.

30. -Stare at the eye of the red parrot while you count slowly to 20, then look immediately at one spot in the empty bird cage. The faint, ghostly image of the blue green bird will appear in the cage. -Try the same thing with the green cardinal. A faint magenta bird will appear in the cage.

34. ADAPTATION Dark adaptation = rods & cones become more sensitive to light (entering a dark room) Dark adaptation = rods & cones become more sensitive to light (entering a dark room) Light adaptation = r & c become less sensitive (leaving dark room into light) Light adaptation = r & c become less sensitive (leaving dark room into light)

35. VISUAL ACUITY Sharpness of vision Sharpness of vision Determined by the ability to see visual details Determined by the ability to see visual details

37. Corrective Lenses