1. 1. Vision Stimulus: Light (Elecro-magnetic radiation) Receptor: Cones and Rods

2. Approximately –6-7 million cones –75-150 million rods Cones are most sensitive to color and higher levels of light Rods most effective in lower light conditions, black and white etc.

4. Light Energy

5. Cornea

6. Light Energy Cornea Refracts (bends) the light

7. Light Energy Cornea Refracts (bends) the light Focused through the pupil

8. Light Energy Cornea Refracts (bends) the light Focused through the pupil Iris Contracts or dilates to allow more or less light

9. Light Energy Cornea Refracts (bends) the light Focused through the pupil Iris Contracts or dilates to allow more or less light Light enters the lens

10. Light Energy Cornea Refracts (bends) the light Focused through the pupil Light enters the lens Bends and focuses Light Energy Iris Contracts or dilates to allow more or less light

11. Light Energy Cornea Refracts (bends) the light Focused through the pupil Light enters the lens Bends and focuses Light Energy Image is inverted and displayed on the retina Iris Contracts or dilates to allow more or less light

12. Light Energy Cornea Refracts (bends) the light Focused through the pupil Light enters the lens Bends and focuses Light Energy Image is inverted and displayed on the retina Transduction Iris Contracts or dilates to allow more or less light

13. Light Energy Cornea Refracts (bends) the light Focused through the pupil Light enters the lens Bends and focuses Light Energy Image is inverted and displayed on the retina Transduction Transfer of Light Energy to Neural impulses on photo-receptor cells Iris Contracts or dilates to allow more or less light

14. Light Energy Cornea Refracts (bends) the light Focused through the pupil Light enters the lens Bends and focuses Light Energy Image is inverted and displayed on the retina Transduction Iris Contracts or dilates to allow more or less light Transfer of Light Energy to Neural impulses on photo-receptor cells Chemical changes in bipolar and ganglion cells activate rods and cones

15. Light Energy Cornea Refracts (bends) the light Focused through the pupil Light enters the lens Bends and focuses Light Energy Image is inverted and displayed on the retina Transduction Iris Contracts or dilates to allow more or less light Transfer of Light Energy to Neural impulses on photo-receptor cells Chemical changes in bipolar and ganglion cells activate rods and cones Cones create neural impulse for color and rods create impulse for shape, border and night vision

16. Light Energy Cornea Refracts (bends) the light Focused through the pupil Light enters the lens Bends and focuses Light Energy Image is inverted and displayed on the retina Transduction Iris Contracts or dilates to allow more or less light Chemical changes in bipolar and ganglion cells activate rods and cones Cones create neural impulse for color and rods create impulse for shape, border and night vision Impulses channeled to the Optic Nerve Transfer of Light Energy to Neural impulses on photo-receptor cells

17. Light Energy Cornea Refracts (bends) the light Focused through the pupil Light enters the lens Bends and focuses Light Energy Image is inverted and displayed on the retina Transduction Iris Contracts or dilates to allow more or less light Chemical changes in bipolar and ganglion cells activate rods and cones Cones create neural impulse for color and rods create impulse for shape, border and night vision Impulses channeled to the Optic Nerve Transfer of Light Energy to Neural impulses on photo-receptor cells Impulse travels through the thalamus, then (if worthy) on to the visual cortex in the occipital lobe

18. Light Energy Cornea Refracts (bends) the light Focused through the pupil Light enters the lens Bends and focuses Light Energy Image is inverted and displayed on the retina Transduction Iris Contracts or dilates to allow more or less light Chemical changes in bipolar and ganglion cells activate rods and cones Cones create neural impulse for color and rods create impulse for shape, border and night vision Impulses channeled to the Optic Nerve Transfer of Light Energy to Neural impulses on photo-receptor cells Impulse travels through the thalamus, then (if worthy) on to the visual cortex in the occipital lobe Visual cortex processes impulses into an image

19. Light Energy Cornea Refracts (bends) the light Focused through the pupil Light enters the lens Bends and focuses Light Energy Image is inverted and displayed on the retina Transduction Iris Contracts or dilates to allow more or less light Chemical changes in bipolar and ganglion cells activate rods and cones Cones create neural impulse for color and rods create impulse for shape, border and night vision Impulses channeled to the Optic Nerve Impulse travels through the thalamus, then (if worthy) on to the visual cortex in the occipital lobe Visual cortex processes impulses into an image Perception Occurs Transfer of Light Energy to Neural impulses on photo-receptor cells

20. Binocular Vision Monocular depth cues allow us to see in 3D with one eye, but it’s best with both –Because left and right eyes see things a little differently – binocular disparity The combination of two images into the one we see –Example: Finger Sausage

21. Color Blindness 8% of Men 1% of Women Usually red and green Sometimes yellow and Blue Very few are totally color blind

23. After Image A visual impression that persists after the removal of the stimulus which originally caused it. –Example: American Flag, Jesus

25. Autosereogram Illusion of depth through binocular cues Formed by superimposing 2 repeating patterns, which are slightly offset