PHOTORECEPTION

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PHOTORECEPTION

• EYES AND VISION

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Electromagnetic Spectrum
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herapies/lighttherapy/spectrum.JPG
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http//www.ems.psu.edu/Courses/earth002/03012D.gif
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Types of Eyes
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The Rod
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Lacrimal Gland and Duct
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Extrinsic Muscles of the Eye
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Anatomy of the Eye
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Image Pathway
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The Eye
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Lens and its Function
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ACCOMMODATION
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THE RETINA
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Layers of the Retina
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Retina
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A Rod
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Comparison of Rods and Cones

• Rods Cones
• used for night vision used for day vision
• very light sensitive not very light
  sensitive sensitive to scattered
  light sensitive only to direct light
• loss causes night blindness loss causes legal
  blindness
• low visual acuity high visual acuity
• not present in fovea concentrated in fovea
• 20 times more rods than cones in the retina
• one type of photosensitive pigment three types
  of photosensitive pigment in humans
• confer achromatic vision confer color vision

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OPTIC DISK AND MACULA LUTEA
Optic Disk
Macula Lutea
Fovea Centralis
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Density of Rods Cones
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Wavelength Sensitivity of Receptors
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Sensitivity of the Moth Eye
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Stimulation of Photopigment
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Transduction
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Stimulation of Photo-receptor