1. The eye – curved cornea – lens – retina – fovea – optic disk Using Light

2. photoreceptors transduce incoming light ganglion cells send signals along to the brain The Retina has layers of cells

3. 2 types of photoreceptors: rods and cones rods are very sensitive - useful in dim light Two kinds of Photoreceptors

4. Rods and cones are distributed differently across the retina The Retina

5. visual acuity (ability to see detail) depends on cones - thus acuity varies across the visual field The Retina

6. Why don’t you notice your blind spot? The Retina

7. Why don’t you notice your blind spot? – Blindspots don’t overlap! – Your brain “fills in” the missing information – The specific information in the blindspot isn’t much more missing than the rest of the periphery! The Retina

8. three types of cones: short, medium, and long different absorptions enable color vision The Retina

9. Ganglion cells project to the brain via the optic nerve information is projected to contralateral cortex! Visual Pathways

10. Seeing Depth What’s the big problem with seeing depth ?

11. Seeing Depth The world is 3D, the retina is 2D !

12. Depth Cues Four categories: 1. Pictorial 2. Physiological 3. Motion 4. Stereoscopic

13. Depth Cues  Pictorial Depth Cues: aspects of 2D images that imply depth

14. Depth Cues  Pictorial Depth Cues: aspects of 2D images that imply depth  Physiological Depth Cues: Proprioception in ocular muscles indicates accommodation and convergence

15. Depth Cues  Pictorial Depth Cues: aspects of 2D images that imply depth  Physiological Depth Cues: Proprioception in ocular muscles indicates accommodation and convergence  Motion Depth Cues: foreground and background move in opposite directions

16. Depth Cues  Pictorial Depth Cues: aspects of 2D images that imply depth  Physiological Depth Cues: Proprioception in ocular muscles indicates accommodation and convergence  Motion Depth Cues: foreground and background move in opposite directions  Stereoscopic Depth Cues: disparity between two retinal images indicates distance

17. Pictorial Depth Cues – Occlusion

18. Pictorial Depth Cues – Occlusion

19. Pictorial Depth Cues – Shadows and Shading

20. Pictorial Depth Cues – Shadows and Shading

21. Pictorial Depth Cues – Shadows and Shading: visual system assumes light from above

22. Pictorial Depth Cues – Shadows and Shading: visual system assumes light from above

23. Pictorial Depth Cues – Shadows and Shading