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NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
NW2005 Color vision
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NW2005 Color vision

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  • 1. Color Vision ณวัฒน์ วัฒนชัย กิติกล ลีละวงค์ ุ
  • 2. Visual process ht lig object light source refle ct e d ligh t/co lor eye
  • 3. Electromagnetic spectrum
  • 4. Visible light  normally visible light 400-700 nm  except : beta peak (380-400 nm)  infant  aphakic condition
  • 5. color vision  how we can see all these colors?
  • 6. AnaToMy
  • 7.  Visual process     light pass through cornea/AC/lens/vit absorption by the rod/ cone photoreceptors retinal neural circuit  horizontal cells  bipolar cells  ganglion cells optic nerve higher visual centers  LGB (parvocellular portion)  Cortex
  • 8. Rod and Cone photoreceptors
  • 9. Rod and Cone photoreceptors <400 nm 400-700 nm >700 nm
  • 10. Rod photoreceptors     92 millions (100M) no rod in central 0.25 mm of fovea peak at 5-7 mm from foveal center decrease number with age
  • 11. Rod photoreceptors    mediate vision at low illumination levels (scotopic) 108 range of illumination from near darkness to daylight critical flicker threshold 20 Hz
  • 12. Cone photoreceptors     4.6 millions (5M) highest density at macula stable numbers, no relationship to age Mediate best vision at daylight levels (photopic)
  • 13. Cone photoreceptors    Responsible for good visual acuity and color perception 1011 range of illumination from moonlight nights to very very bright light critical flicker threshold 55-60 Hz
  • 14. Rods and Cones together   Mesopic photopic + mesopic + scotopic = 1014 range of illumination
  • 15. no rod in central 0.25 mm of fovea, peak between 5-7 mm from foveal center, while cone has highest density at macula  this distribution means  midperiphery of VF  the greatest light sensitivity (night vision)  fovea  high acuity, good color vision
  • 16. Rod and Cone photoreceptors     Rod SWS cone MWS cone LWS cone (B-cone) (G-cone) (R-cone) 507 nm 445 nm 543 nm 566 nm
  • 17. Gene Encoding the Human Photopigments chromosome 3  Rhodopsin  Iodopsin (SWS) chromosome 7 Iodopsin (MWS,LWS) chromosome X 
  • 18. Cone cells S cones - longer inner segment larger inner segment deeper innervation patchwork mosaic low at fovea, peak 1 degree all ~ 10% L, M cones - very similar dense hexagonal packing L/M ~ 2/1 all ~ 90%
  • 19. genes : L, M cones  located on chromosome X tandem array ~ 2-6 (1 LWS, >1 MWS) hybrid  protan (red-blind)  deutan (green-blind)
  • 20. Horizontal cells 1. 2. 3. - H1 dendrite all cones-axon-rod H2 contact S cones avoid others H3 avoid S cones contact others local-circuit neurons chromatic organization opponent color coding first stage of wavelength discrimination ?
  • 21. Bipolar cells For rod : on-cell type (single depol.) For cone : off and on-cell type Depolarize (on) : depol. Response to central/direct illumination Hyperpolarize (off) : hyperpol. To center illumination and depol. To surround illumination
  • 22. Ganglion cells - - - Its axons form optic nerve and terminate at LGB/ other diencephalic centers/ superior colliculus earliest visual neuron to generate true action potential neural coding in term of frequency of firing spatial/color opponent organization functional classification P & M
  • 23. Ganglion cells Property P cells color selectivity yes receptive field size small luminance contrast low cell size small conduction velocity low response time course tonic function in scotopic no number of cells 1,000,000 M cells no large (~10 times high large high phasic yes 100,000
  • 24.  optic nerve  LGB  cortex/ other centers
  • 25. Color vision 11 basic color term 4 uniques hue : red yellow green blue 3 achromatic color: black white gray other 4 color : orange purple brown pink
  • 26. Basic Aspects of Color Vision human can perceived 8000 colors at a single luminance level  at optimal cone vision (1000  luminance range) – 8,000,000 sh ades and tints can be distinguishe d
  • 27. Theory of color reception   theory of trichromacy theory of opponent color  opponent cells  double opponent cells
  • 28. Color vision : color system 1 CIE color system Commission international del’Ecalirage specific luminance proportion x + y + z = 1 3 dimension 2 dimension spectral/non-spectral color white center
  • 29. . W
  • 30. Color vision : color system 2 Munsell color system - - cylinder - hue (spectral color) 10 x10 ( R Y G ) Circumferential - value (lightness) up/down - chroma (whiteness) radial
  • 31. Factors that modified color vision       Brightness Saturation State of dark adaptation : Perkinje effect Adjacent cone : lateral inhibition Fatique and after image Optical factors : lens, macula, chromatic aberration, Stile-Crawford effect
  • 32. Colorless objects that appear colored  Blue sky : blue – easier scattered
  • 33. Colorless objects that appear colored  red sunset
  • 34. Colorless objects that appear colored  blue water
  • 35. Color Vision Defect what is color?!?!? moo.o..o...
  • 36. Color Vision Defects Normal trichromats 92%  Dyschromatopsia 8% 
  • 37. Classification of hereditary color defect red ano. Trichromats Protanomal Dichromats Monochromats Protanope green Deuteranomal blue Tritanomal Deuteranope Tritanope Blue cone monochromats Rod monochromats
  • 38. Dyschromatopsia  Anomalous trichromatism  Protanomaly XR   XR Tritanomaly AD Dichromatism  Protanopia XR  Deuteranopia XR  Tritanopia AD Monochromatism  Rod monochromatism AR  cone monochromatism XR   Deuteranomaly 1% 5% 0.0001% 1% 1% 0.0001% 0.001% UK
  • 39. Congenital red-green defect    most common male 8%, female 0.5% Cause  Deletion of R-G pigment gene  Hybridization of R-G gene
  • 40. Congenital red-green defect
  • 41. Congenital red-green defect  Characteristics  symmetrically binocular  constant in type and severity through out life  normal VA/ fundus/ photoERG  name the color correctly
  • 42. HUE DISCRIMINATION DEFECT
  • 43. Acquired color vision abnormality  Characteristics  VA & VF defect  Generally varied in type and severity  Unstable severity
  • 44. Acquired color vision abnormality  charateristics  Affect one eye or asymmetrically affect  Use incorrect color name or report that familiar color appearance has changed
  • 45. Acquired color-vision abnormality Kollner’ rule B/Y : retinal/choroid receptor/outer plexiform R/G : neural disorder ganglion cell
  • 46. Kollner’s rule Retinal diseases : B/Y Eg: RD, RP, ARMD, myopic degen, chorioretinitis, CRVO, DR, CSCR Except : cone-dystrophy, Stargardt’s
  • 47. Kollner’s rule Optic nerve diseases : R/G Eg: optic neuritis, ON compression, LHON, toxic optic neuropathy Except : AD optic atrophy, glaucoma, AION, OHT
  • 48. Acquired/hereditary color defect characteristics - Color- naming - unilateral/bilateral - blue-yellow - change/ unstable - other visual symtoms
  • 49. Color Discrimination    Hue Saturation (chroma) Brightness (luminance, intensity)
  • 50. 1. Hue Discrimination     hue  wavelength depend on proportion of cone output better in intersected sensitivity function cross point of pigment absorption sensitivity yellow(590) red/green blue-green(490) green/blue
  • 51. Hue Discrimination
  • 52. 1. HUE DISCRIMINATION
  • 53. 2.Saturation  color purity fully saturated color : only 1 wavelength for visible light  desaturated color : add white light  perception  depth of color (dark/ light blue) 
  • 54. 2. Saturation Saturation - how much of one hue must be add to white to be distinguished - the more amount, the less saturation - many variables purity, intensity, size, time
  • 55. 2. SATURATION SENSITIVITY yellow – lowest saturation
  • 56. 3. Luminosity relative brightness/lightness peak absorption photopic 555 scotopic 507 Purkinje shift (rod & blue cone pathway?)
  • 57. 3. LUMINOSITY CURVE 507 555
  • 58. Color vision tests
  • 59. Color vision tests Patient selection - screening test in children, student, worker - undiagnosed low vision - recent color disturbance - Family Hx of color defect - Occupations
  • 60. Color vision tests  Ideal color vision test  Detect the presence or absence of normal color vision  Distinguish between R-G and B-Y defect  Assess the severity of defect  comfortable
  • 61. Color vision tests 1. 2. 3. Screening test Color discrimination test Color matching test
  • 62. Color vision test 1: screening test 1. Color confusion 1. Ishihara test 2. FD15 test 2. Color saturation 1. AO-HRR test 2.TMC plate
  • 63. Color vision test : Ishihara test - Test R-G - High sensitivity for congen R-G defect
  • 64. Color vision test : AOHRR test - 24 plates - Color defect or not - Assess severity (+/-) R-G and B-Y -
  • 65. Color vision : FD-15 - Farnsworth D-15 - line of confusion - R/G,B/Y - separate color handicap
  • 66. FD-15
  • 67. FD-15
  • 68. Color vision tests 1. 2. 3. Screening test Color discrimination test Color matching test
  • 69. Color vision test 2 : discrimination    Hue discrimination  FM-100  Farnsworth desaturated panel D-15  Lanthony new color test Lightness discrimination  Verriest’s lightness discrimination Saturation discrimination  Sahlgren’s saturation test
  • 70. Color vision test 2 : discrimination  ใช้เวลามาก  อาศัยความชำานาญ  ไม่เหมาะกับ routine exam  ไม่เหมาะกับเด็กอายุนอยกว่า 10 ปี ้
  • 71. Farnsworth-Munsell 100 hue test - 85 caps in 4 groups hue discrimination test serial color order within 2 min /each group position&number of error score
  • 72. FM 100 hue test  Goals  Grading of color discrimination in normal subjects (superior/ average/ low)  Find zone of color confusion
  • 73. Farnsworth-Munsell 100 hue test
  • 74. Color vision tests 1. 2. 3. Screening test Color discrimination test Color matching test
  • 75. Color vision 3 : matching Anomaloscope 1. Nagel R/G red640 + green545 = yellow589 2. Pickford-Nicolson B/Y, R/G 3. Sloan’s achromatopsia test grading severity Expense
  • 76. ไม่เ ห็น รู้เ รื่อ ง เลย...ย......... ?

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