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Optics of Vision

Optics of Vision

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Optics of Vision

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  1. Optics of Vision Light refraction

  2. Optics of Vision

  3. Optics of Vision Refraction power a lens “Diopter” = 1 m / focal length

  4. Optics of Vision

  5. Optics of Vision

  6. Picture Formation cataracts (opacities in the lens)

  7. Picture Formation • Lens accommodation • Pupil adjustment • Fusion of the two eyes

  8. Optics of Vision

  9. Optics of Vision

  10. Accommodation

  11. Accommodation

  12. Accommodation

  13. Vision problems Ametropia: refraction error, inabiulity of properly focusing light on the retina, a frequent reason for reduced visual acuity

  14. Vision problems

  15. Accommodation Presbyopia: Loss of accommodation by the lens

  16. Vision problems Astigmatism : irregular curvature of either the cornea or the lens, which lead to blurred or distorted vision due to parts of the image are out of focus.

  17. Accommodation and parasympathetic

  18. Pupillary Adjustment

  19. Pupillary Adjustment

  20. Visual acuity • Normally , people has the ability to distinguish contours that are approximately 1.75 mm apart at 6 meters distance from the eye

  21. Visual acuity • Normally , people has the ability to distinguish contours that are approximately 1.75 mm apart at 6 meters distance from the eye

  22. Photoreceptors Cones Rods

  23. Color Blindness

  24. Color Blindness Red-green color blindness

  25. Color Blindness • Red-green color blindness • X linked

  26. Color Blindness • Red-green color blindness • X linked • Deuteranope >>> green • Protanope >>> red • Tritanopia >>> Blue Chromosome 7 • ***anomaly : shift in the spectrum of one of the proteins i.e. Deuteranomaly, Protanomaly, Tritanopia

  27. Color Blindness

  28. Color Blindness Protanopia Deuteranopia Tritanopia

  29. Color Blindness Protanopia Deuteranopia Tritanopia

  30. Color Blindness Protanopia Deuteranopia Tritanopia

  31. Color Blindness

  32. Color Blindness

  33. Color Test Chart 74 VS 21

  34. Color Test Chart 42 VS 4 “green” / 2 “red”

  35. In conclusion The colorblind have a narrowed color perception. Green is still green and red stays red most of the time, but not as vibrant or bright as a non colorblind would see it. Colors lie closer to each other, especially shades of colors.

  36. VISUAL PATHWAY

  37. The retinohypothalamic pathway • day/night cycle • Melanopsin ganglionic cells

  38. Visual Pathways The optic nerve has two principle branches