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NETRA on SIGGRAPH 2010

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Our Presentation at ACM SIGGRAPH 2010.

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NETRA on SIGGRAPH 2010

  1. 1. NETRA: Interactive Display for Estimating Refractive Errors and Focal Range<br />Vitor Pamplona Ankit Mohan Manuel M. Oliveira RameshRaskar<br />1<br />
  2. 2. 2<br />NETRA: Near Eye Tool for Refractive Assessment<br />Vitor Pamplona Ankit Mohan Manuel M. Oliveira RameshRaskar<br />
  3. 3. Challenge<br />2B have<br />refractive errors<br />0.6B have URE<br />4.5B have a <br />cell phone<br />6.5 Billion <br />people<br />NETRA at LVP Eye Institute<br />3<br />
  4. 4. 4<br />Computational Photography<br />Optometry/Opthalmalogy<br />Measure .. Overcome Limitations .. Extend Abilities<br />
  5. 5. Accuracy<br />Sharpness Estimation is subjective<br />Brightness affects results<br />Pupil size variation and DoF<br />Cost<br />Trial Lens Set > $150<br />Bulky<br />Snellen chart<br />Phoropter<br />Trial lenses<br />Reading Charts<br />
  6. 6. Needs expert, Moving parts, Shining lasers<br />* Phoropter-based: $5,000.00<br />
  7. 7. Shack-Hartmann Wavefront Sensor<br />Wavefrontaberrometer<br />Expensive; Bulky, Requires trained professionals<br />7<br />
  8. 8. Shack-Hartmann Wavefront Sensor<br />Laser<br />Sensor<br />8<br />Shack & Platt 1971<br />Liang et al 1994<br />David Williams et al, Rochester<br />Spot Diagram<br />Planar Wavefront<br />Microlens Array<br />Shack-Hartmann ~ Lightfields<br />Levoy et al 2009 <br />Zhang and Levoy 2009: Observable Light Field<br />Oh, Raskar, Barbastathis 2009: Augmented Light Field <br />
  9. 9. Shack-Hartmann Wavefront Sensor<br />Laser<br />Spot Diagram<br />9<br />Sensor<br />Displacement = Local Slope of the Wavefront<br />
  10. 10. NETRA= Inverse of Shack-Hartmann<br />10<br />Spot Diagram on LCD<br />Cell Phone Display<br />Eye Piece<br />
  11. 11. 11<br />Inverse of Shack-Hartmann<br />User interactively creates the Spot Diagram<br />Spot Diagram on LCD<br />Displace 25 points but 3 parameters<br />
  12. 12. Optometry<br />Infinity<br />Subject <br />can focus<br />at infinity<br />Human Eye<br />Accommodation Range<br />Normal Vision<br />10cm<br />Infinity<br />12<br />
  13. 13. Myopia (nearsightedness)<br />Infinity<br />Subject <br />cannot focus<br />at far distances<br />Accommodation Range<br />Normal Vision<br />Shifted Accommodation Range<br />Myopia<br />10cm<br />Infinity<br />13<br />
  14. 14. Myopia Correction<br />Infinity<br />Subject <br />can focus<br />at infinity<br />Human Eye<br />Accommodation Range<br />Normal Vision<br />Shifted Accommodation Range<br />Myopia<br />10cm<br />Infinity<br />14<br />
  15. 15. Myopia Correction<br />Infinity<br />Subject <br />can focus<br />at infinity<br />Divergent Lens<br />Human Eye<br />Accommodation Range<br />Normal Vision<br />Corrected Myopia<br />Myopia<br />10cm<br />Infinity<br />15<br />
  16. 16. Hyperopia (farsightedness)<br />Infinity<br />Wrong <br />focal point<br />Human Eye<br />Accommodation Range<br />Normal Vision<br />Myopia<br />Hyperopia<br />10cm<br />Infinity<br />16<br />
  17. 17. Hyperopia (farsightedness)<br />‘Beyond’<br />Infinity<br />Human Eye<br />Accommodation Range<br />Normal Vision<br />Myopia<br />Hyperopia<br />10cm<br />Infinity<br />17<br />
  18. 18. Hyperopia Correction<br />Infinity<br />Convergent Lens<br />Human Eye<br />Accommodation Range<br />Normal Vision<br />Myopia<br />Hyperopia<br />10cm<br />Infinity<br />18<br />Corrected Hyperopia<br />
  19. 19. Refractive Errors and Shifted Range<br />Perfect vision<br />Need to measure<br />Myopia<br />Hyperopia<br />10cm<br />Infinity<br />19<br />1m<br />33cm<br />Distance<br />
  20. 20. Refractive Errors and Shifted Range<br />Perfect vision<br />Myopia<br />Hyperopia<br />10cm<br />Infinity<br />20<br />1m<br />33cm<br />Distance<br />10D<br />0D<br />3D<br />1D<br />-1D<br />-3D<br />Diopter<br />Diopter = 1/Distance<br />
  21. 21. Relaxed Eye with Myopia<br />Eye<br />Red pointat infinity<br />Blurred <br />point<br />Focusing Range<br />perfect vision<br />myopia<br />hyperopia<br />~10cm<br />infinity<br />21<br />
  22. 22. Relaxed Eye with Myopia<br />Eye<br />Pinholes<br />Distinct<br />image <br />points<br />Red pointat infinity<br />Focusing Range<br />perfect vision<br />Scheiner’s Principle<br />myopia<br />hyperopia<br />~10cm<br />infinity<br />22<br />
  23. 23. Relaxed Eye with Myopia<br />Eye<br />Display<br />A<br />Distinct<br />image <br />points<br />Virtual red pointat infinity<br />B<br />Focusing Range<br />perfect vision<br />myopia<br />hyperopia<br />~10cm<br />infinity<br />23<br />
  24. 24. Relaxed Eye with Myopia<br />Eye<br />Display<br />Move spots towardseach other<br />A<br />Distinct<br />image <br />points<br />Virtual red pointat finite distance<br />B<br />Focusing Range<br />perfect vision<br />myopia<br />hyperopia<br />~10cm<br />infinity<br />24<br />
  25. 25. Relaxed Eye with Myopia<br />Eye<br />Display<br />Move spots towardseach other<br />A<br />Points <br />overlap<br />Virtual red pointat finite distance<br />B<br />Focusing Range<br />perfect vision<br />myopia<br />hyperopia<br />~10cm<br />infinity<br />25<br />
  26. 26. Relaxed Eye with Myopia<br />Eye<br />Display<br />Move spots towardseach other<br />A<br />Points <br />overlap<br />Virtual red pointat finite distance<br />B<br />Focusing Range<br />perfect vision<br />myopia<br />hyperopia<br />~10cm<br />infinity<br />26<br />
  27. 27. Relaxed Eye with Myopia<br />Eye<br />Points <br />overlap<br />Point at infinity<br />Focusing Range<br />perfect vision<br />myopia<br />hyperopia<br />~10cm<br />infinity<br />27<br />
  28. 28. Relaxed Perfect Eye <br />Display<br />A<br />Points <br />overlap<br />Virtual red pointat infinity<br />B<br />Focusing Range<br />perfect vision<br />myopia<br />hyperopia<br />~10cm<br />infinity<br />28<br />
  29. 29. Relaxed Eye with Hyperopia<br />29<br />Eye<br />Display<br />A<br />Distinct<br />image <br />points<br />Virtual red pointat infinity<br />B<br />Focusing Range<br />perfect vision<br />myopia<br />hyperopia<br />~10cm<br />infinity<br />
  30. 30. Relaxed Eye with Hyperopia<br />Move spots awayfrom each other<br />Display<br />Display<br />A<br />Points <br />overlap<br />B<br />Virtual point“beyond” infinity<br />Focusing Range<br />perfect vision<br />myopia<br />hyperopia<br />~10cm<br />infinity<br />30<br />
  31. 31. Relaxed Eye with Hyperopia<br />Move spots awayfrom each other<br />Points <br />overlap<br />Virtual point“beyond” infinity<br />Focusing Range<br />perfect vision<br />myopia<br />hyperopia<br />~10cm<br />infinity<br />31<br />
  32. 32. NETRA: Using pinholes<br />32<br />Pinhole array<br />Patterns on an LCD<br />
  33. 33. NETRA: Using Lens to Increase Light<br />Microlensarray<br />Patterns on an LCD<br />a<br />f<br />33<br />t<br />Pixel Pitch<br />Virtual Depth<br />
  34. 34. Interactive Method<br />Farthest Focal Point<br />(myopia, hyperopia)<br />34<br />
  35. 35. Interactive Method<br />35<br />Farthest Focal Point<br />(myopia, hyperopia)<br />
  36. 36. Interactive Method<br />Farthest Focal Point<br />(myopia, hyperopia)<br />36<br />
  37. 37. Overview<br />37<br /><ul><li>Inverse of Shack Hartmann Wavefront Sensor
  38. 38. Hi-res displays + interaction
  39. 39. Measuring Spherical Error
  40. 40. No moving parts, lasers
  41. 41. Blur -> Alignment problem
  42. 42. ~ Lightfield Display for Single Eye
  43. 43. Astigmatism
  44. 44. Novel Patterns
  45. 45. Focal Range
  46. 46. User Study</li></li></ul><li>Astigmatism: angle-dependent refractive error<br />http://www.elizabethpope.co.uk/eyeinfo/astigmatism.html<br />38<br />
  47. 47. Astigmatism: angle-dependent refractive error<br />http://www.elizabethpope.co.uk/eyeinfo/astigmatism.html<br />39<br />
  48. 48. Astigmatism: angle-dependent refractive error<br />http://www.elizabethpope.co.uk/eyeinfo/astigmatism.html<br />40<br />
  49. 49. Refractive Power as a Function of Angle<br />41<br />Axis Cyl.<br />Cylinder<br />Unknowns:<br />Sphere<br />
  50. 50. Astigmatism<br />Cross or points may never meet with a 1d search !<br />42<br />
  51. 51. Astigmatism<br />Lines reduce the problem to a 1d search<br />43<br />
  52. 52. Interactive Method<br />Farthest Focal Point<br />(myopia, hyperopia, astigmatism)<br />44<br />
  53. 53. Interactive Method<br />Farthest Focal Point<br />(myopia, hyperopia, astigmatism)<br />45<br />
  54. 54. Interactive Method<br />Farthest Focal Point<br />(myopia, hyperopia, astigmatism)<br />46<br />
  55. 55. Interactive Method<br />Farthest Focal Point<br />(myopia, hyperopia, astigmatism)<br />47<br />
  56. 56. Interactive Method<br />Farthest Focal Point<br />(myopia, hyperopia, astigmatism)<br />48<br />
  57. 57. Evaluation Prototype<br />Camera simulates<br />the perfect eye<br />Trial lenses simulate lens aberration<br />Minification<br />LCD Display<br />49<br />
  58. 58. Subjective Validation: User Study<br />50<br />
  59. 59. Measuring the Accommodation Range<br />51<br />Myopia<br />Perfect vision<br />Hyperopia<br />~10cm<br />Infinity<br />Step 2: Near limit<br />Step 1: Far limit<br />
  60. 60. Measuring the Accommodation Range<br />52<br />Myopia<br />Perfect vision<br />Hyperopia<br />~10cm<br />Infinity<br />Step 2: Near limit<br />Step 1: Far limit<br />
  61. 61. Measuring the Accommodation Range<br />53<br />Myopia<br />Perfect vision<br />Hyperopia<br />~10cm<br />Infinity<br />Step 2: Near limit<br />Step 1: Far limit<br />
  62. 62. Relaxed Eye <br />Display<br />A<br />Points <br />overlap<br />Virtual Point at the far limit<br />B<br />54<br />
  63. 63. Accommodated Eye <br />Display<br />Move points towards each other<br />A<br />Points <br />overlap<br />B<br />55<br />Virtual pointgetting closer<br />Subject Accommodates <br />to fix the “blur” <br />
  64. 64. Accommodated Eye <br />Display<br />Move points towards each other<br />A<br />Points <br />overlap<br />B<br />56<br />Virtual pointgetting closer<br />Subject Accommodates <br />to fix the “blur” <br />
  65. 65. Accommodated Eye <br />Display<br />Move points towards each other<br />A<br />Points <br />overlap<br />B<br />57<br />Virtual pointgetting closer<br />Subject cannot accommodate more than the previous point<br />
  66. 66. Patterns for Alignment Task<br />58<br />A<br />B<br />A<br />B<br />A<br />B<br />A<br />B<br />A<br />B<br />Displayed<br />Subject view<br />A<br />B<br />A<br />B<br />A<br />B<br />A<br />B<br />A<br />B<br />Displayed<br />Subject view<br />Visual <br />Cryptography<br />[NaorShamir94]<br />
  67. 67. Patterns for Alignment Task<br />59<br />A<br />B<br />A<br />B<br />A<br />B<br />A<br />B<br />A<br />B<br />Displayed<br />Subject view<br />A<br />B<br />A<br />B<br />A<br />B<br />A<br />B<br />A<br />B<br />Displayed<br />Subject view<br />Visual <br />Cryptography<br />[NaorShamir94]<br />
  68. 68. Subject View as Convolution<br />Display<br />Subject’ s View <br />Subject’ s View<br />
  69. 69. Subject View<br />Viewmaster prototype<br />61<br />+3D to -5D with accommodation<br />Scaled Patterns <br />G(0D)<br />G(+5D)<br />G(-5D)<br />h - Jittered Pinholes<br />
  70. 70. Summary of Interaction<br />Accommodation Range<br />Farthest Point<br />(myopia, hyperopia, astigmatism)<br />NearestPoint<br />(presbyopia)<br />62<br />
  71. 71. Limitations<br />Children<br />Ability to align lines<br />Single Eye test<br />Other eye for convergence-forced accommodation<br />Resolution is a function of the display DPI<br />Samsung Behold II – 160 DPI – 0.35D<br />Google Nexus One – 250 DPI – 0.2D<br />Apple iPhone 4G – 326 DPI – 0.14D<br />63<br />
  72. 72. Future Work<br />Clinical research for an optometry device<br />Side-by-side validation tests<br />Field trials <br />Tests for cataract, lazy eye, etc<br />Opportunity to monitor one’s eyesight<br />Diabetes/Glucose non-invasive meter<br />Unstable lens prescriptions<br />Distribution in Developing Countries<br />Software app for free<br />Eyepiece blueprint to NGOs for <$1<br />More at EyeNetra.com<br />64<br />
  73. 73. Future Work<br />Multi-focus display without moving parts<br />[Akeley04][Rolland00][Hua09] [Barsky04]<br />Personalized devices (clear without glasses) <br />Alarm Clock <br />Cell phones<br />eReaders<br />65<br />Inju<br />Fernando Meyer<br />
  74. 74. Acknowledgements<br />Volunteers<br />Dr. Joseph Ciolino (MGH Mass Eye and Ear Inst.)<br />Dr. Fuentanta Vera Diaz (Schepens Eye Research Inst.)<br />Dr. James Kobler (MGH Mass Eye and Ear Inst.)<br />Dr. ShrikantBhardwaj, (LV Prasad Eye Institute, India)<br />Sponsors<br />CNPq-Brazil<br />Alfred P. Sloan Research Fellowship<br />Google <br />Samsung <br />66<br />
  75. 75. NETRA: Display for Eye Refraction Tests<br />Inverse of Shack-Hartmann wavefrontaberrometer<br />High-resolution displays and user interaction<br />Focal Parameters<br />Myopia, Hyperopia, Astigmatism<br />Focal range<br />Thermometer for the eye<br />Measurement not prescription<br />Promote Self Awareness<br />Impact in Developing Countries<br />600 Million without corrective glasses<br />$1 cost, easy to deploy<br />67<br />
  76. 76. NETRA: Interactive Display for Estimating Refractive Errors and Focal Range<br />Vitor Pamplona Ankit Mohan Manuel M. Oliveira RameshRaskar<br />68<br />
  77. 77. Computing <br />A<br />B<br />69<br />
  78. 78. 70<br />Display<br />g<br />h<br />
  79. 79. Books<br />71<br />
  80. 80. Contributions<br />Dual of the Shack-Hartmann system<br />Interface sensitive to refractive parameters of the eye<br />Four designs for the optical probe<br />Interactive method to create objects at desired depths<br />Patterns study for optimal alignment and accommodation<br />Method to measure refractive errors for far and close fields<br />Validation <br />Physical lens measurements <br />User study compared with current prescriptions<br />72<br />
  81. 81. Final Interactive Method<br />Accommodation Range<br />Farthest Focal Point<br />(myopia, hyperopia, astigmatism)<br />NearestFocal Point<br />(presbyopia)<br />73<br />
  82. 82. Partnerships for the Optometric Device<br />Vicky<br />LVP<br />Side-by-side testing<br />Field testing<br />Deployment partner<br />74<br />
  83. 83. Patterns Study<br />Displayed<br />Subject view<br />2nd<br />3rd<br />1st<br />Displayed<br />Subject view<br />75<br />
  84. 84. Measuring Accommodation Range<br />Displayed<br />Subject view<br />Displayed<br />Subject view<br />76<br />
  85. 85. Spherical: -0.5 diopters<br /> Cylindrical: -1.0 diopters<br /> Astigmatism Axis: 10°<br /> Accommodation Range: -5.07 diopters<br /> Sharp Focus Range: from 18cm to 2m<br />Estimated Prescription<br />-1.0<br />-0.5<br />10°<br />-1.0<br />Standard Prescription<br />Extra Info.<br />77<br />
  86. 86. Focusing Rangeand Refractive Errors<br />eye<br />perfect vision<br />need to measure<br />~25mm<br />myopia<br />hyperopia<br />~10cm<br />infinity<br />cornea<br />(~40D)<br />crystalline lens<br />(10~20D)<br />78<br />
  87. 87. Focusing Rangeand Refractive Errors<br />eye<br />perfect vision<br />~25mm<br />myopia<br />hyperopia<br />presbyopia<br />~10cm<br />infinity<br />cornea<br />(~40D)<br />crystalline lens<br />(0~10D)<br />79<br />
  88. 88. Head Mounted Display Prototype<br />0.5um microlensarray with spacer<br />resolution: 0.35D<br />LCD display<br />1806 dpi<br />80<br />
  89. 89. Samsung prototype<br />lcd: 180dpi<br />pinhole:a=3mm <br />lenslet:f=20mm<br />resolution: 0.71D<br />cost: ~$2 (pinhole)<br />resolution: 0.71D<br />controls<br />pinhole or microlens array with spacer<br />display patterns <br />audio feedback<br />81<br />
  90. 90. Nexus One prototype<br />lcd: 250dpi<br />pinhole: a=3mm, <br />lenslet: f=20mm<br />resolution:0.4D<br />cost: ~$2 (pinhole)<br />resolution: 0.4D<br />pinhole or microlens array with spacer<br />display patterns <br />controls<br />audio feedback<br />82<br />
  91. 91. Human Eye<br />Human Eye<br />cornea<br />(~40D)<br />crystalline lens<br />(10~20D)<br />83<br />
  92. 92. Normal Vision<br />Infinity<br />Subject <br />can focus<br />at infinity<br />Human Eye<br />Accommodation Range<br />Normal Vision<br />30cm<br />Infinity<br />84<br />
  93. 93. Myopia<br />High-curvature cornea<br />Increased refractive power<br />Relaxed crystallin<br />Infinity<br />Subject <br />cannot focus<br />at far distances<br />Human Eye<br />Accommodation Range<br />Normal Vision<br />Myopia<br />30cm<br />Infinity<br />85<br />
  94. 94. Myopia Correction<br />Relaxed Crystallin<br />Infinity<br />Subject <br />can focus<br />at infinity<br />Divergent Lens<br />Human Eye<br />Accommodation Range<br />Normal Vision<br />Corrected Myopia<br />Myopia<br />30cm<br />Infinity<br />86<br />
  95. 95. Hyperopia<br />Planar cornea<br />Decreased refractive power<br />Infinity<br />Human Eye<br />Accommodation Range<br />Normal Vision<br />Myopia<br />Hyperopia<br />30cm<br />Infinity<br />87<br />
  96. 96. Hyperopia<br />Planar cornea<br />Decreased refractive power<br />Subject accommodates to compensate for flat cornea<br />Infinity<br />Subject <br />can focus<br />at infinity<br />Human Eye<br />Accommodation Range<br />Normal Vision<br />Myopia<br />Hyperopia<br />30cm<br />Infinity<br />88<br />
  97. 97. Hyperopia Correction<br />Now, subject <br />can focus<br />at infinity<br />without<br />accommodation<br />Infinity<br />Convergent Lens<br />Human Eye<br />Accommodation Range<br />Normal Vision<br />Myopia<br />Hyperopia<br />Corrected Hyperopia<br />30cm<br />Infinity<br />89<br />
  98. 98. vs<br />Snellen chart<br />NETRA<br />smaller, less bulky, easier to carry<br />little no training required<br />allows self-evaluation<br />cheaper (if phone already exists)<br />trial lenses<br />phoropter<br />90<br />
  99. 99. Health Screening Tools<br />Blood Oxygenation<br />Blood Pressure<br />Visual Accommodation<br />Body Temperature<br />Blood Glucose<br />91<br />
  100. 100. Photography in 1960s<br />Photo: IllanaTamir<br />Photo: Roboppy<br />Expensive and bulky equipment<br />Requires specialized training<br />Very slow process<br />Mostly manual process<br />Go to a place to take the picture<br />Photo: Azigog<br />92<br />
  101. 101. Today, cameras are everywhere<br />Photo: Tyler<br />Photo: Derek K. Miller<br />Photo: John Kannenberg<br />But the photographer is still there!<br />93<br />
  102. 102. Optometry Today<br />Corneal Topographer<br />Wavefront Aberrometer<br />Phoropter<br />Expensive and bulky equipment<br />Require specialized training<br />Very slow process<br />Mostly manual process<br />Go to a place to get your eyes tested<br />94<br />
  103. 103. NETRA: Interactive Display for Measuring Refractive Error and Focal Range<br />95<br />
  104. 104. Astigmatism: radially asymmetric error<br />Cross or points may never meet with a 1d search<br />96<br />
  105. 105. Astigmatism<br />Lines reduce the problem to a 1d search<br />97<br />
  106. 106. Measuring Accommodation Range<br />98<br />
  107. 107. Normal Vision<br />Infinity<br />Subject <br />can focus<br />at infinity<br />Human Eye<br />Accommodation Range<br />Normal Vision<br />30cm<br />Infinity<br />99<br />
  108. 108. Normal Vision<br />30cm<br />Infinity<br />Normal Vision<br />Accomodation:<br />Increase optical power<br />30cm<br />Subject <br />can focus<br />close<br />Human Eye<br />Accommodation Range<br />100<br />
  109. 109. Myopia<br />High-curvature cornea<br />Increased refractive power<br />Relaxed crystallin<br />Infinity<br />Subject <br />cannot focus<br />at far distances<br />Human Eye<br />Accommodation Range<br />Normal Vision<br />Myopia<br />30cm<br />Infinity<br />101<br />
  110. 110. Myopia<br />High-curvature cornea<br />Increased refractive power<br />Little or no accomodation<br />Subject <br />can focus<br />close<br />Human Eye<br />Accommodation Range<br />Normal Vision<br />Myopia<br />30cm<br />Infinity<br />102<br />
  111. 111. Myopia Correction<br />Relaxed Crystallin<br />Infinity<br />Subject <br />can focus<br />at infinity<br />Divergent Lens<br />Human Eye<br />Accommodation Range<br />Normal Vision<br />Corrected Myopia<br />Myopia<br />30cm<br />Infinity<br />103<br />
  112. 112. Hyperopia<br />Planar cornea<br />Decreased refractive power<br />Subject accommodates to compensate for flat cornea<br />Infinity<br />Subject <br />can focus<br />at infinity<br />Human Eye<br />Accommodation Range<br />Normal Vision<br />Myopia<br />Hyperopia<br />30cm<br />Infinity<br />104<br />
  113. 113. Hyperopia<br />Planar cornea<br />Decreased refractive power<br />Insuficient accommodation<br />for near vision<br />Subject <br />cannot focus<br />close<br />Human Eye<br />Accommodation Range<br />Normal Vision<br />Myopia<br />Hyperopia<br />30cm<br />Infinity<br />105<br />
  114. 114. Hyperopia Correction<br />Now, subject <br />can focus<br />at infinity<br />without<br />accommodation<br />Infinity<br />Convergent Lens<br />Human Eye<br />Accommodation Range<br />Normal Vision<br />Myopia<br />Hyperopia<br />Corrected Hyperopia<br />30cm<br />Infinity<br />106<br />
  115. 115. Computational Photography<br />Every one of us carries 3 cameras: <br />All of them have aberrations<br />107<br />
  116. 116. Camera Closest Focal Point<br />108<br />
  117. 117. Human Closest Focal Point<br />109<br />
  118. 118. Spherical Lens Measurement<br />Average error in 6 measurements for each green dot<br />Prototype Resolution: 0.16 diopters<br />110<br />
  119. 119. Spherical: -0.5 diopters<br />Cylindrical: -1.0 diopters<br /> Astigmatism Axis: 90°<br />Estimated Prescription<br />111<br />
  120. 120. Spherocylindrical Lens Measurement<br />Average absolute errors:<br /><ul><li>Spherical: 0.09 +/- 0.056 diopters
  121. 121. Cylindrical: 0.23 +/- 0.19 diopters
  122. 122. Axis: 8.43 +/- 6.16 degrees</li></ul>Spherical<br />Cylindrical<br />Prototype Resolution: 0.16 diopters<br />112<br />
  123. 123. Prescription User Study<br />Average absolute errors:<br /><ul><li> Spherical and Cylindrical: 0.5 +/- 0.2 diopters
  124. 124. Axis: 6 degrees</li></ul>113<br />
  125. 125. Hyperopia (farsightedness)<br />Subject accommodates to compensate for flat cornea<br />Infinity<br />Subject <br />can focus<br />at infinity<br />Planar cornea<br />Decreased refractive power<br />Human Eye<br />Accommodation Range<br />Normal Vision<br />Myopia<br />Hyperopia<br />10cm<br />Infinity<br />114<br />
  126. 126. Hyperopia Correction<br />Now, subject <br />can focus<br />at infinity<br />without<br />accommodation<br />Infinity<br />Convergent Lens<br />Human Eye<br />Accommodation Range<br />Normal Vision<br />Myopia<br />Hyperopia<br />Corrected Hyperopia<br />10cm<br />Infinity<br />115<br />
  127. 127. Astigmatism: angle-dependent refractive error<br />http://www.elizabethpope.co.uk/eyeinfo/astigmatism.html<br />116<br />
  128. 128. Astigmatism: angle-dependent refractive error<br />http://www.elizabethpope.co.uk/eyeinfo/astigmatism.html<br />117<br />
  129. 129. Astigmatism: angle-dependent refractive error<br />http://www.elizabethpope.co.uk/eyeinfo/astigmatism.html<br />118<br />
  130. 130. Interactive Method<br />Farthest Focal Point<br />(myopia, hyperopia)<br />119<br />
  131. 131. Interactive Method<br />Farthest Focal Point<br />(myopia, hyperopia)<br />120<br />
  132. 132. Interactive Method<br />Farthest Focal Point<br />(myopia, hyperopia)<br />121<br />
  133. 133. Measured data against prescriptions<br />13 volunteers<br />Average error:<br />Spherical and Cylindrical: 0.5 +/- 0.2 diopters<br />Axis: 6 degrees<br />Without eye drops to relax accommodation<br />We do not have control over the prescription<br />122<br />
  134. 134. Measuring lens power with an SLR camera<br />108 measurements for spherical Lenses:<br />Maximum average error of 0.09 diopters<br />8 measurements for spherocylindrical Lenses. <br />Avg. Spherical Error: 0.09 +/- 0.056 diopters<br />Avg. Cylindrical Error: 0.23 +/- 0.19 diopters<br />Avg. Axis Error: 8.43 +/- 6.16 degrees<br />123<br />
  135. 135. Validation 1: Cameras<br />Measuring closest focal point for cameras<br />124<br />
  136. 136. Validation 2: People<br />Measuring closest sharp point for 6 volunteers<br />125<br />
  137. 137. Evaluation Prototype<br />Camera simulates<br />the perfect eye<br />Pinhole or micro lens array with spacer<br />Minificationrelay optics <br />3,320 DPI<br />LCD Display<br />126<br />
  138. 138. Astigmatism<br />127<br />Axis Cyl.<br />Cylinder<br />Sphere<br />
  139. 139. Astigmatism<br />128<br />Axis Cyl.<br />Cylinder<br />Sphere<br />
  140. 140. Astigmatism<br />129<br />Axis Cyl.<br />Cylinder<br />Sphere<br />

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