1. L.A.S.E.R.
    • Light 
    • Amplification by 
    • Stimulated 
    • Emissions of 
    • Radiation
  2. Spectacle Lens Material (3)
    • 1)CR-39= Columbia Resin 39; Cheapest
    • 2)Polycarbonate=safety lenses, used by=children, construction workers, and monocular patients
    • 3)High Index= most expensive, for high perscriptions 
    • *AR and Scratch resistant coating recommended
  3. Photoablation
    • scraping away
    • used UV light (193 nm)
    • called excimer
    • use Ar and Fluorine
    • used for PRK, LASIK, LASEK, PTK
  4. Photocoagulation
    • hot lasers used to thermally destroy tissue; burn tissue
    • most common Argon Laser (Blue/Green 488-515nm)
    • krypton laser (red 647nm)
    • used for Mascular Degenteration and Diabetic Retinopathy
    • used to destroy blood vessels that are leaking
  5. Photodisruption
    • cold laser used to destroy tissue by creating microexplosions
    • Nd-YAG (1064nm) 
    • used to destroy blood vessels that are leaking
    • used to open up posterior capsule opacities
    • helps move cells away from line of vision
  6. Interfaces
    • interface--     vergence--   power
    • 1-air-tear---positive---Plus
    • 2-tear-anterior cornea--positive--Plus
    • 3-posterior cornea-aqueous--negative--minus
    • 4-aqueous-anterior lens--positive--plus
    • 5-posterior lens-vitreous--positive--plus
  7. Densities of the Eye(4)
    Air----1.000-----Less Dense

    • Tear----1.336
    • Aqueous
    • Vitreous 


    Lens-------------------more dense
  8. Layers of the Eye(6)
    • 1-tears
    • 2-cornea
    • 3-anterior humor
    • 4-lens
    • 5-vitreous
    • 6-retina
  9. Milli-
    10^-3; 3 units below basic
  10. Kilo-
    10^3; 3 units above the basic
  11. The refractive index cannot be greater than 1.0 because....
    top number greater than bottom denometer will always be less than numerator therefore RI will always be greater than 1.0
  12. Formula for Refractive Index
    • RI(n)=speed of light in a vaccuum
    •          speed of light in a medium
  13. colors in electromagnetic spectrum
  14. Laser are: (3)
    • 1-monochromatic (one color)
    • 2-single wavelength
    • 3-light is parallel coherent (a stream of light)
  15. Fluorescence
    • a light particle
    • wavelength of fluorescing light is longer than the wavelength the wavelength of excitation light
    • most common in OMT--Fluorescein sodium ophthalmic dye
  16. Destructive Interference
    when two waves are out of phase crests and trough DO NOT travel together the total effect of this is subtractive
  17. Angle of Refration
    the angle between a refracted light ray and the normal to a surface upon the light ray strickes
  18. Deci-
    10^-1; 1 unit below basic
  19. Speed of Light
    • c=3X10^10cm/sec
    • c=3X10^8m/sec
  20. photon
    light as a particle, fluorescence
  21. Wavelength lengths for light
    • 400-700nm 
    • violet-Red
  22. Constructive Interference
    If waves are exactly in phase and their crests and troughs travel together; they will add to each other and the total effects will become additive
  23. Fact: from less dense to more dense refractive ray bends towards the normal
    Fact: from more dense to less dense refractive ray bends away from the normal
  24. Polarization
    • once unpolarized light hits a surface it reflects off and becomes polarized 
    • horizantal polarized light is very bothersome to humans
    • polarized sunglasses use vertically polarized spectacle lenses are used to eliminate horizantally polarized light, decreasing the glare
  25. Centi-
    10^-2; 2 units below basic
  26. Meters (m)
    units for length
  27. Grams (g)
    units for weight
  28. Angle of Incidence
    the angle between an incident light ray and the normal to a transparent surface upon the light ray strikes
  29. Snell's Law (3 possibilities)
    • 1-when the refracted ray bend towards the normal--less-->more dense
    • 2-when the refracted ray bend way from the normal--more-->less dense
    • 3-when the refracted ray doesn't bend-->90degrees
  30. Liters(l)
    units for volume
  31. Critical Angle
    goes from a more dense material to a less dense material bending away from the normal; when the angle of incidense grazes the interface coming closer and closer if angle goes over the interface it becomes the angle of reflection
  32. Total Internal Reflection
    • requires that 1)light passes from a medium of greater refractive index
    • 2) the angle of incidence exceeds the critical angle
  33. Gonioscopy
    • looking at angle
    • putting lenses on the eye to eliminate air; use mirror; look inside the eye at an angle *Goldmanlens* Koeppe lens*
  34. Diamonds
    • TIR
    • cosmetic
    • cutting faces into them to get TIR shinyness
    • increase faces increase value
  35. Optical Fibers
    • example of TIR 
    • industrial computers 
    • fastest way to transfer material
  36. Hyperopia
    • ametropia 
    • any thing less than +62D lens 
    • need a + lens to correct
  37. Myopia
    • ameropia
    • anything greater than +62
    • need a - lens to correct
  38. Emmotrops
    the "perfect" eye +62D
  39. Prisms bend ______ the base.
  40. minus lens (prisms)
    prisms=apex to apex
  41. plus lens (prisms)
    prisms=base to base
  42. The eye is a giant_____lens.
  43. Divergence
    a negative or minus vergence and provides a minus power
  44. Convergence
    a positive or plus vergence and provides a plus power
  45. The greater the curvature the ______ the power.
  46. Light traveling at 90 degrees goes______.
  47. Meniscus Lens
    Both surfaces on the lens are curved
  48. Lens
    a refracting device in which at least one surface is curved
    • 0---+14---Loss
    • 8---+14 
    •           +1D/4yrs
    • 40---+6
    •            +1.5D/4yrs
    • 44---+4.50
    •             +1.5D/4yrs
    • 48---+3
    •           +0.5D/4yrs
    • 72---+0
  50. Presbyopia
    gradual loss of accommodation with increase of age
  51. uncorrected astigmatism
    people complain of tilting or slanting or they see ghosts requires cyl lens
  52. Cylinder
    power is not the same all over
  53. Sphere
    D is same in all direction
  54. Astigmatism
    • condition in the eye that elongates the image cylinders are used to correct
    • *can be from cornea and/or lens
  55. Cylindrical (-) creates a______.
    virtual image, elongates
  56. Cylindrical (+) creates a ______.
    real image, elongated
  57. sphere (-) creates a ______.
    virtual image focal image
  58. sphere (+) creates a ______.
    real image, focal point
Card Set