This document discusses progressive addition lenses (PALs) and how to properly fit them. PALs provide uninterrupted vision at all distances without visible lines but require careful fitting. The fitting process involves identifying patient needs, selecting an appropriate frame, adjusting the frame measurements, determining pupil distance, marking the lens insert position, checking the fit, and delivering instructions. Common fitting issues include incorrect pupil distance, lens heights, or prescriptions. Proper troubleshooting requires identifying potential causes and remedies through refitting adjustments or remaking lenses. Attention to detail in fitting and addressing patient complaints is important for successful PAL adaptation.

1. PROGRESSIVE
ADDITION
LENSES

2. Aim of any vision correction device
is to provide good vision
i.e. minimum change from natural
vision

3. Options for a Presbyope..
• Single vision lenses
• Bifocals
• Progressive Addition Lenses

4. Single Vision Lenses…
• Corrects only one distance at a time
• Inconvenient
• Cumbersome

5. Bifocals…
• Distinct junction between zones -
Cosmetically unappealing
• Intermediate blur
• Image jump

6. PALs…
• Uninterrupted vision for all distances
• No visible junctions - Cosmetically
appealing
• Convenient
• No differential
displacement

7. If they are so good…
Why aren’t PALs prescribed extensively ??

8. We love the revenue generated

9. But hate it when a patient comes back
with some problem

10. Disadvantages..
• Peripheral aberration
• Some adaptation problems
• More critical fitting
• More expensive

11. Fitting PALs is an art..
It requires adequate training & skill
It involves communication & counselling skills
and convincing power

12. And a science..
It requires :
• A systematic approach
• Understanding of potential problems
• In-depth study of designs

13. A PAL blank..

14. A Layout card..

15. Whom to fit ?
ALL PRESBYOPES !
BUT..

16. Contraindications
Field of View

17. Contraindications
Direction of Gaze

18. Contraindications
Mobility / Head Movement

19. Contraindications
Prescriptions
• Anisometropia / Antimetropia
• High Cylinders
• Prisms

20. Fitting ...

21. Step 1
Identification of
Patient’s
Requirements &
Expectations

22. Useful tip
 Judge the motivation
 Highlight the advantages, but mention
the limitations as well

23. Step 2
Frame Selection

24. Useful tip
Prefer metal frames with adjustable
nose pads

25. Step 3
Frame Adjustment
Adjust before taking facial
measurements
Adjust when delivering spectacles

26. Step 3
Frame Adjustment
Back vertex Distance - shorter

27. Step 3
Frame Adjustment
Pantoscopic Tilt - 10 to 12 degrees

28. Step 3
Frame Adjustment
Facial wrap - must not be too flat

29. Step 4
Monocular PD

30. Step 4
Monocular PD
61
Monocular PD Monocular PD
29 32

31. Step 5
Monocular PD

32. Step 6
Marking the lens insert

33. Step 7
Fitting height

34. Useful tip
Natural head posture
Sit at the same level as the patient
Check binocularly from a dist. of 1 metre
Use a fine marker

35. Step 8
Checking the cut out

36. Delivery ..
Markings
Distance power & prism
Addition
Fitting cross heights & PDs

37. Delivery ..
On eye assessment
Frame fit Fitting crosses

38. Delivery ..
On eye assessment
Distance Vision Near Vision

39. Delivery ..
Delivery Instructions

40. Useful tip
Use positive language
Remove the markings at the end
Maintain a record of the order forms

41. Trouble shooting ...
When & Why ?

42. Factors in Adaptation ...
Motivation
Expectations
Education & Encouragement
Occupation & hobbies

43. Sources of errors ...
Heights
Monocular PDs
Swapped lenses
Wrong power & axis

44. Complaints & Remedies...
PROBLEM
Blurry Distance Vision Possible Causes
• Fitting too high
• Incorrect Rx
Remedies
• Open the nose pads
• Remake lenses

45. Complaints & Remedies...
PROBLEM
Blurry Near Vision Possible Causes
• Fitting too low
• Inadequate pantoscopic
tilt
• Incorrect Rx
Remedies
• Bring in nose pads
• Frame adjustments
• Remake lenses

46. Complaints & Remedies...
PROBLEM
Swimmy Sensation Possible Causes
• Incorrect PD & heights
• Inadequate pantoscopic
tilt
• Facial Wrap
• Adaptation
Remedies
• Increase facial wrap
• Pantoscopic tilt

47. Complaints & Remedies...
PROBLEM Possible Causes
Reading area too small • Incorrect PD
• Fitting heights too low
Remedies
• Frame adjustments
• Refit lenses

48. Complaints & Remedies...
PROBLEM
Possible Causes
Having to look to the side
• Incorrect PD
to read
• Swapped lenses
Remedies
• Refit to correct PDs
• Swap lenses if frame
symmetrical

49. Complaints & Remedies...
PROBLEM
Possible Causes
Having 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. Complaints & Remedies...
PROBLEM Possible Causes
Having to tilt head • Undercorrected
hyperope
backward for distance
• Overcorrected myope
Remedies
• Repeat the refraction
• Refit lenses

51. Complaints & Remedies...
PROBLEM Possible Causes
Having to tilt head • Add too strong
forward to read
• Remedies
• Repeat the refraction
• Refit lenses

52. Complaints & Remedies...
PROBLEM Possible Causes
Having to tilt head • Fitting height too high
forward for distance
Remedies
• Frame adjustment
• Refit lenses

53. Summary...
Key to problem solving is a systematic
approach