Progressive Spectacle Lens Fitting

15,332 views

Published on

6 Comments
31 Likes
Statistics
Notes
No Downloads
Views
Total views
15,332
On SlideShare
0
From Embeds
0
Number of Embeds
1,409
Actions
Shares
0
Downloads
0
Comments
6
Likes
31
Embeds 0
No embeds

No notes for slide

Progressive Spectacle Lens Fitting

  1. 1. PROGRESSIVE ADDITION LENSES
  2. 2. Aim of any vision correction device is to provide good visioni.e. minimum change from natural vision
  3. 3. Options for a Presbyope..• Single vision lenses• Bifocals• Progressive Addition Lenses
  4. 4. Single Vision Lenses… • Corrects only one distance at a time • Inconvenient • Cumbersome
  5. 5. Bifocals…• Distinct junction between zones - Cosmetically unappealing• Intermediate blur• Image jump
  6. 6. PALs…• Uninterrupted vision for all distances• No visible junctions - Cosmetically appealing• Convenient• No differential displacement
  7. 7. If they are so good… Why aren’t PALs prescribed extensively ??
  8. 8. We love the revenue generated
  9. 9. But hate it when a patient comes back with some problem
  10. 10. Disadvantages..• Peripheral aberration• Some adaptation problems• More critical fitting• More expensive
  11. 11. Fitting PALs is an art..It requires adequate training & skillIt involves communication & counselling skillsand convincing power
  12. 12. And a science..It requires :• A systematic approach• Understanding of potential problems• In-depth study of designs
  13. 13. A PAL blank..
  14. 14. A Layout card..
  15. 15. Whom to fit ?ALL PRESBYOPES ! BUT..
  16. 16. Contraindications Field of View
  17. 17. Contraindications Direction of Gaze
  18. 18. ContraindicationsMobility / Head Movement
  19. 19. ContraindicationsPrescriptions • Anisometropia / Antimetropia • High Cylinders • Prisms
  20. 20. Fitting ...
  21. 21. Step 1Identification of Patient’s Requirements & Expectations
  22. 22. Useful tip Judge the motivation Highlight the advantages, but mention the limitations as well
  23. 23. Step 2Frame Selection
  24. 24. Useful tipPrefer metal frames with adjustablenose pads
  25. 25. Step 3 Frame AdjustmentAdjust before taking facialmeasurementsAdjust when delivering spectacles
  26. 26. Step 3Frame AdjustmentBack vertex Distance - shorter
  27. 27. Step 3 Frame AdjustmentPantoscopic Tilt - 10 to 12 degrees
  28. 28. Step 3 Frame AdjustmentFacial wrap - must not be too flat
  29. 29. Step 4Monocular PD
  30. 30. Step 4Monocular PD 61 Monocular PD Monocular PD 29 32
  31. 31. Step 5Monocular PD
  32. 32. Step 6Marking the lens insert
  33. 33. Step 7Fitting height
  34. 34. Useful tipNatural head postureSit at the same level as the patientCheck binocularly from a dist. of 1 metreUse a fine marker
  35. 35. Step 8Checking the cut out
  36. 36. Delivery ..MarkingsDistance power & prismAdditionFitting cross heights & PDs
  37. 37. Delivery ..On eye assessment Frame fit Fitting crosses
  38. 38. Delivery ..On eye assessment Distance Vision Near Vision
  39. 39. Delivery .. Delivery Instructions
  40. 40. Useful tipUse positive languageRemove the markings at the endMaintain a record of the order forms
  41. 41. Trouble shooting ... When & Why ?
  42. 42. Factors in Adaptation ...MotivationExpectationsEducation & EncouragementOccupation & hobbies
  43. 43. Sources of errors ...HeightsMonocular PDsSwapped lensesWrong power & axis
  44. 44. Complaints & Remedies... PROBLEMBlurry Distance Vision Possible Causes • Fitting too high • Incorrect Rx Remedies • Open the nose pads • Remake lenses
  45. 45. Complaints & Remedies... PROBLEMBlurry Near Vision Possible Causes • Fitting too low • Inadequate pantoscopic tilt • Incorrect Rx Remedies • Bring in nose pads • Frame adjustments • Remake lenses
  46. 46. Complaints & Remedies... PROBLEMSwimmy Sensation Possible Causes • Incorrect PD & heights • Inadequate pantoscopic tilt • Facial Wrap • Adaptation Remedies • Increase facial wrap • Pantoscopic tilt
  47. 47. Complaints & Remedies... PROBLEM Possible CausesReading area too small • Incorrect PD • Fitting heights too low Remedies • Frame adjustments • Refit lenses
  48. 48. Complaints & Remedies... PROBLEM Possible CausesHaving to look to the side • Incorrect PD to read • Swapped lenses Remedies • Refit to correct PDs • Swap lenses if frame symmetrical
  49. 49. Complaints & Remedies... PROBLEM Possible CausesHaving to tilt head too far • Incorrect PD back to read • Add too weak • Change in design Remedies • Bring in nose pads • Increase the add • Refit lenses
  50. 50. Complaints & Remedies... PROBLEM Possible CausesHaving to tilt head • Undercorrected hyperopebackward for distance • Overcorrected myope Remedies • Repeat the refraction • Refit lenses
  51. 51. Complaints & Remedies... PROBLEM Possible CausesHaving to tilt head • Add too strongforward to read • Remedies • Repeat the refraction • Refit lenses
  52. 52. Complaints & Remedies... PROBLEM Possible CausesHaving to tilt head • Fitting height too highforward for distance Remedies • Frame adjustment • Refit lenses
  53. 53. Summary...Key to problem solving is a systematic approach

×