dispensing optics selection frame fitting

1. OPTICAL DISPENSING
Dr Solanki Optometry Department

2. Over view
 • Definition
 • Frame style/Cosmetic Dispensing
 • Frame measurement
 • Spectacles Instrument Accessories
 • Counselling
 • Ophthalmic lens fitting

3. Definition
• An optical dispensing is sub specialty of
optometry which includes all procedures from
the time the glass prescription is presented to
the optician, till the patients are on with the
pair the glasses satisfactorily.

4. Frame style/cosmetic
dispensing
Follow these steps to choose a best stylish eyeglass
frames.

5. Determining facial wrap
 Broadly, there are six face shapes that we
observe around the world.
 Oval
 Round
 Square
 Rectangle
 Triangular
 Heart

6. Oval Face shape
Oval face shape is the most common face shape
and is considered as an ideal one
recommend oversized or rectangular frames

7. Round Face shape
Round faces are usually proportional to width
and length that features your full cheeks and a
broad forehead.
recommended rectangular or angular frames
for round face shaped persons.

8. Square Face shape
• Square faces are characterized by a broad
squares forehead and a strong jaw line.
• We recommended Round or Oval shaped
frame.

9. Rectangle face shape
• Rectangle faces are regarded as the elongated
proportion that means a longer, narrower face
and nose, along with the
same strong jaw line and
squares forehead.
• We recommended round
or cat eye shaped

10. Triangle face shape
• Triangle face have a narrow forehead, but
wider cheek.
• These faces look the best in top heavy styles
which help balance out the jaw.

11. Heart face shape
• Heart shaped faces have a broad forehead and
narrow jaw line or small chin.
• We recommended deep vertical frame shaped
frame.

12. Frame Measurements
• Datum system
• Boxing system

13. Datum system
• Previously used system for measuring lenses,
was established as a system of reference points
for the frames & lenses
so that position of lens optical centres & bifocal
segment heights would be consistent

14. Boxing System
• In 1962 the optical manufacturers association
adopted the boxing system to provide a
standard
for frame and lens measurement that greatly
improved upon the accuracy of previous
systems.
• The boxing system is based upon the idea of
drawing an imaginary box around a lens shape
with the box’s sides tangent to the outer most
edges of the shape.

16. Frame measurement guide

17. “A” MESURMENT
• It is measured as the horizontal distance
between the furthest temporal and nasal edges
lens shape of the box.
• This is measured in millimetres

18. “B” MESURMENT
• It is measured as the vertical distance between
the furthest top and bottom edges lens shape
of the box.

20. Pre dispensing measurement
• Facial wrap
• Pantascopic tilt
• Vertex distance
• IPD measurement
 PD ruler
 Pupillometer
 Pen torch

21. • Facial wrap
facial wrap the frame fills properly
following
the curved line of the face.
• Pantascopic tilt
Pantascopic tilt is the angle between
the normal
to the temple and frame front.
• Vertex distance
Vertex distance is the distance
between the front
of the cornia and back of the lens.

22. Spectacles Instrument
accessories
PD measurement devices
• PD ruler
• Pupillometer
• Pen torch & marker

23. PD Ruler Method
• Sit directly opposite the patient (arm’s length)
• Position yourself 40cm in front of the patient.
• Eyes are level.
• Place ruler on the bridge of the patient’s nose
• Hold pen torch under your left eye directed
at the patient’s RE

24. • The dispenser aligns the zero mark
of the
demo lens with the centre of patient’s
pupil.
• The PD for distance is read as the
mark falling
on the left pupil.

25. The Pupilometer method
• Fast and accurate measurement
for monocular and binocular
PDs.
• The variation between
the visual axes and
pupil centre.

26. Pupilometer
• Procedure:
 Hold the instrument in both hands and rest the
pupilometer
on patients face.
 Ability to vary working distance from 20cm to
infinity
 Internal hairline moved until line and corneal
reflection are
coincident
 Corneal reflection typically located nasal to pupil
center (2
to 5 )

27. Subject’s view
Practitioner’s
view

28. Direct pupillary reflex marking
 A pen torch will produce clear corneal
reflections.
 Position yourself 40cm in front of the patient.
 Eyes are level
 Hold a pen light under your left eye, aiming
the light at the patient’s eye.
 Mark the patient corneal reflex in marker.

29. • Mark the patient corneal reflex in
marker.

30. Layout card measurment
• Measure monocular PD. The recommended
procedure is the use of a pupillometer.
• Incorrect PD may cause difficulty in using
different zones through the lens.

31. Counselling
• Lens materials
 Glass
 Plastic
 Hi-index etc
 Lens Design
 Single vision
 Bifocal
 Executive
 Progressive etc

32. • Lens coating
 ARC
 SRC
 UV OR Polarized
• Photo chromatic
• Tinted lens

33. Lens material
Traditionally, people used to prefer glass lenses. But
they have become less popular now due to the
danger of breaking. They are also heavier in weight
than alternatives. These days, CR-39 plastic lenses
are the preferred material for spectacle lenses.
It is safer, cost effective and offers an outstanding
optical quality. some people would be satisfied
with just that-a cheap good quality lens which can
correct vision.

34. • People become more aware, they’ve
started
realizing there is more to it than it appears.
Like UV protection, even lighter weight,

35. Lens Coating
• Every good lens has 3-4 coatings,
• Each of a microscopic thickness.
• Most common of coatings is for toughening the
lenses to make it break-resistant.
• Then UV protection coating and Scratch resistant.
• Lastly, there is the anti-reflective coating
Primarily helps in reducing the
effect of reflective light from
bright objects such lamps or
car headlights at night.

36. UV Protection and Polarized
lens
This is one of the major deciding factors. UV
exposure has been clinically proven to be an
important cause of cataract because of its
oxidative effects on humans.

37. Photo chromatic
• A major breakthrough in the area of absorptive
lenses took place in 1964 with the invention of
corning’s photo gray photo chromatic.
• These lenses darken when exposed to light.
• photo chromatics are available in both glass
and plastic material.

38. Tinted lenses
• A tint is usually associated with a certain
quantity and depth of color, the depth of color
is described as density of lens.
• Both glass and plastic lenses can be tinted to
achieve the desired color.

39. Ophthalmic Lens fitting
Laying off
• Before a lens is edged it must be marked so
that cylinder axis if any is set according to
prescription and its optical centre is in correct
position relative to lens shape.
• We use a lenso meter to mark three dots
indicating optical centre position and the
horizontal meridian.

40. • These horizontally placed dots are used to
set
the lens on correct axis.
• In case of bifocals and trifocal and trifocals
the
three dots should be parallel to top of the
segment.

41. Lens cutting
• Once the lens is layed off it must now be cut
into desired shape.

42. Edging formers
• Shanking tongs were then used
to crumble the edge away until
it roughly resembles eye shape.

43. Lens Edging formers
• Flat edge
• Bevel edge
• Mini bevel edge
• Grooved edge

44. Flat Edge
• This is the simple form of edge.
• It is mainly used for lenses fitted
to rimless mounts or as an
intermediate stage in the
production of other edge forms.

45. Bevel Edge
• The bevel edge is used for
lenses to be fitted in shall
and full rimmed frames.
• To avoid pressure on the
peak of bevel and the attendant risk of
chipping the lens

46. Mini Bevel
• The peak of a normal bevel lies approximately
midway between the two surfaces with strong
minus lenses and high cylindrical power.

47. Grooved Edge
• It is simply a flat edge with central groove.
• Used mainly on lenses fitted to spectacles of
the nylon supras or semi rimless types.

48. Hand Edgers
• A hand edger is still indispensable piece os
equipment although new automatic are being
preferred. For starting ensure that the hand edging
machine in good working condition. It should be set
up with adequate water. Hold the lens is both hands
with convex side up. Rest your hands on the dip
tray
and press the lens against the revolving diamond
wheel. Make sure to hold the lens across the wheel
and at a slight upward angle. Now slowly rotate the
lens passing the grip of lens from hand to hand.

49. • After edging match size of edged lens with the
frame. The lens is right when the shape is
exactly like that of the frame to be fitted.
• PHOTO

50. THANK YOU