dispensing optics

1. manjushalakshmi

2. Standard alignment of plastic
frame
HEATING THE FRAME
 Standard plastic frames must be heated for any
alignment.
 Standard procedure for adjusting the frame should be
followed, beginning with the bridge.
 Frame may be heated using
 Hot Salt or Glass Beads
 Forced Hot Air

3. WITH HOT AIR:
1. Heat only the portion of the frame to be worked on.
2. Rotate the frame in the heat. (This is especially
important for warmers having heat coming from one
direction only.)
3. Check the type of frame material. Some materials
can stand more heat than others.

4. WITH SALT OR BEADS:
1. Ask yourself, “Should this frame material or these
lenses be subjected to salt or beads?” If there is
any doubt, use hot air.
2. Always stir the salt (or glass beads) first.
3. Keep the area of the frame being heated parallel to
the surface of the salt.
4. Keep the frame moving slowly.
5. Heat only the portion of the frame to be worked on

5. An example of a frame that has been overheated,
resulting in bubbling of the plastic on the upper rim.

6. THE BRIDGE
 A number of thing may be error in relation to bridge
 The bridge itself mainly judged by the effect it has on
the plane of lenses
 Readjusting the lenses to their proper plane is done by
heating the bridge area, then grasping the frame by
lens area and adjusting according to the correction
needed

7. Adjustment using salt pan
 Place the frame in the
pan temples up and
through the peak of salt
mount
 Repeat this until the
bridge is flexible enough
to be bent

8. Adjustment using forced hot air
 When using hot air concentrate the air stream on
bridge
 Move the bridge through the hot air stream until it
become flexible
 Then it can adjusted to desired correction

9.  If the lens is deviated from horizontal plane they are
said to be out of horizontal alignment
 If the lens is deviated from vertical plane they are said
to be out of vertical alignment

10. Horizontal alignment
 To check for horizontal alignment, place a ruler
or straight edge across the back of the frame at the top
of the pads
 If there are no pads, there may be a point where the
sculptured shaping of the bridge area ends .
 Both end pieces should be equidistant from the
straight edge when it is aligned horizontally. A
practiced eye may be more helpful than a rule

11. There are two common causes for a frame being out of
horizontal alignment:
• a rotated lens
• a skewed bridge.

12. Rotated lens
 A lens rotated in the frame will cause the top of the
eyewire to either hump up at the nasal bridge or one
endpiece to appear upswept in shape
 To correct the problem, use lens rotating pliers.

14. Skewed bridge
 When viewed from the front, a skewed bridge will
cause one lens to appear higher than the other
 This problem usually only happens after the glasses
have been dispensed and something has happened to
them
 To correct a skewed bridge, first heat the bridge, then
grasp the front with an eye wire in each hand
 Force the eye wires in opposite directions until the
tops of the eye wires are parallel.

15. To correct for a skewed bridge,
heat the bridge
and force one side up and the
other down.
An example of a skewed bridge. It
will be noted
that neither of the lenses shows
any twisting. The error is
manifested by one lens being
higher than the other.

16. Vertical Alignment (Four-Point
Touch)
 To check for vertical alignment, or four-point touch,
place a ruler or straight edge so that its edge goes
across the inside of the entire front of the spectacles
below the nosepad area.
 Theoretically the frame eyewire should touch at four
points on the ruler .
 However,this ought to only be the case if the frame is
small compared with the wearer’s head size, otherwise
face form is required.

17. Vertical misalignment
 Face form
 Xing
 Variant Planes

18. Checking for four-point touch. The frame eyewire
touches at each place where the ruler crosses the eyewire. This
indicates correct alignment when the “frame PD” equals the
wearer’s interpupillary distance.

19. Face form or wraparound
 Face form is when the frame front is just slightly rounded to
the form of the face.
 Most frames are constructed with at least a degree of face
form.
 This is especially true of large frames and thick metal
frames.
 Frames with face form will not conform to the fourpoint
touch test, but must be symmetrical nonetheless.
 The temporal sides of the eyewires should touch, and the
nasal sides should be equidistant from the ruler

20.  Too much face form would be evident if the two nasal
eyewires are a great distance from the ruler.
 Too little face form is the case if neither temporal
eyewire, but only the nasal eyewires, touch
 The remedy for either too much or too little face form
is to alter the bridge. First warm the bridge until it is
pliable, then grasp the frame by the lenses and eyewires
with thumbs on the inside and fingers on the outside.
Bend the bridge by turning the lenses inward or outward

22. Xing
 The frame front may be twisted so that the planes of
the two lenses are out of coincidence with each other.
This is called Xing because the eyewires of the frame
front form an X when viewed from the side
 X-ing causes the temples to be out of line with each
other. Whenever the temples do not appear parallel,
the frame
 X-ing is corrected by grasping the eyewires and
rotating the hands in opposing directions until the
planes of the lenses are parallel.

24. In grasping the frame to correct an X-ing error,
the wrists move in opposite directions.

25.  when the lens planes are variant, or out of coplanar
alignment. In this situation, the lens planes are
parallel, but one lens is farther forward than the other
 This error usually becomes apparent when the four-
point touch test is used, although it may easily be
overlooked otherwise
 To correct a frame with lenses out of coplanar
alignment, first heat the bridge and grasp the frame in
the manner.

26. Here is an example of lens planes that are variant
or out of coplanar alignment. In spite of the improperly bent
bridge, the lenses remain parallel to one another.

27. Temple
 After horizontal and vertical pre adjustment have been
done to bridge and eye wire. next accept to consider
how far the temple spared
 To allow a good picture of temple spared temple shaft
must be straight
 Any curve to temple shaft must be eliminated by
heating the temple and straightening with hand

28. Open temple spred
 The open temple spread, or let-back, is that angle that
each open temple forms in relationship to the front of
the frame
 It is the normal condition of the temple to be opened
out slightly farther than a 90-degree angle; usually 94-95
degrees

29. Temple Spread
Temple not spread enough
Temple spread too far
Temple spread unequal

30. Temple spread too far
 Temples fl aring out more
than 95 degrees are spread
too far for standard
alignment
 Glasses tends to slide
down the nose

31. How to correct it ?....
 Too far [bend the temple inwards
 Using the thumb
 Using a fl at surface
 Bend eye wire and endpiece
 Bend the butt portion of the temple
 Sink the hidden hinge deeper into the frame front

32. Using the thumb—
One method of decreasing
temple spread involves
holding the frame by the
lens and eye wire while
pushing the end piece
back with the thumb.

33. Using a fl at surface—
 One of the easiest and
most successful methods
of reducing temple
spread is pressing the
endpiece against a fl at
surface.

34. Bend the butt portion of the
temple—
 Brace both eye wires
with the fore finger and
press the endpiece with
the thumb to decrease
the temple spread.

35. Sink the hidden hinge deeper into
the frame front—
 If no other method
proves successful, it is
possible to bring the
temples in by grasping
the temple butt with
half-padded pliers and
bending the temple with
a free hand.

36. Temple not spread
enough
 Occasionally the temples are not spread enough after
the lenses have been inserted and the bridge area
straightened.
 The lens may not be completely in the frame at the
endpiece.
 The endpiece needs to be bentoutward.
 File the butt end of the temple.
 Bend the temple outward.

37. How to correct it ?....
Not spread enough [bend
the temple outwards
 The lens may not be completely in the frame at the
endpiece.
 The endpiece needs to be bentoutward.
 File the butt end of the temple.
 Bend the temple outward.

38. To spread the temples, heat the endpiece and
pull back with the fi ngers while pressing with the thumbs.

39. Temple parallelism
 In standard alignment the two temple must be parallel
to one another when viewed from the side.
 The flat surface touch test is used to check temple
parallelism:
 Position the glass upside down on a flat surface with
temple open
 Note whether both temple sit flat or one temple is not
touching the flat surface
 Touch the first one temple and the other to see whether
the frame wobble back and forth

40. Causes of incorrect temple
parallelism
 A bend end piece
 A broken rivert and lose hidden hinge
 A bent temple shaft
 A bent hinge
 A twisted bridge