Transcript FreeForm - Mega Optics Limited

FreeForm® Progressives
Welcome
• What is free-form?
• Digital FreeForm lenses vs.
conventional lenses
• General information about the
technology
• Not hard tools needed anymore
• How precise the technology can be
• What can be done by advanced
ophthalmic design and FF
technology?
• Free-form can produce any
ophthalmic lens type
General information about
the technology
• Free form is a manufacturing technology
that allows cutting and polishing arbitrary
surfaces
• A lens is free-form if
– At least one of its surfaces is made with free
form technology and
– That surface is not spherical neither torical*
*Free form machines may cut standard surfaces, but as they can also be cut with standard
methods, the corresponding lenses should not be named free-form lenses.
Not hard tools needed anymore
FreeForm surfacing
•
•
•
•
Blocking
Generating
Polishing
De-blocking
Diamond cutter/sintered diamond milling tool
Flexible tool
How precise the technology
can be
• What is claimed: 0.01 D
• Very difficult to achieve
in plastic
• Well tuned process with
tools, soft pads and
slurries not worn out,
guarantees better
precision than standard
milling and polishing
methods.
What can be done by advanced
ophthalmic design and FF technology?
• Optimize the lens for the power that the user
perceives, not the power measured in the
focimeter (which is ok for quality control, but is
not the power perceived by the user)
• Optimize the lens for any position of use (tilts,
distance to the eye, etc…)
• Optimize the lens for any base curve (the
spherical base curves used with FF lenses)
• Optimize the lens for each prescription
• Optimize the lens for particular applications
• Better control of lens thickness
• Off-centering without losing optical quality
…..
…Important improvement to the optical
quality of standard lenses
Free-form can produce any
ophthalmic lens type
Formation of distortion in progressive lenses
<Conventional PAL>
Formation of distortion in progressive lenses
<Backside PAL>
Distortion in Progressive Lenses
Wider visual field in Backside PAL
Free Form progressive offers
%30 wider visual field
compared to conventional
progressive thanks to the
progressive surface on the
backside of the lenses.
Comparision between FreeForm and
Conventional PAL
Conventional
Based on the geometry of the lens to
calculate the power resulted
Enhanced view mainly in the central
gaze direction
Small degree of lateral unwanted
astigmatism reduction
No personalization option
FreeForm
Based on advanced binocular eyelens system model
Enhanced view whatever the gaze
direction
High degree of lateral unwanted
astigmatism reduction
Personalized lenses
Conventional
vs.
• Smaller Optical visual zones
• More lateral astigmatism
• Higher astigmatism maxims
FreeForm
 Bigger optimal visual zones
 Less astigmatism
 Lower astigmatism maxims
Advanced Ophthalmic digital power structure
Each lens is individually calculated using advanced algorithms to
guaranty an optimized power structure
Symmetrical
structure of the far
power distribution
Symmetrical structure of
the near power
distribution
Inset adjusted to each
wearer
Binocular adaptation
guaranty
Automatic variable inset
Inset (d) calculation method:
Paramteters to be considered
for inset calculation:
s
l’2
Near working distance
NPD
Naso-pupilar distance
P
Distance from lens to eye
center
Prescription
Conventional vs. FreeForm Inset Calculation
Inset not taken into account in
conventional lenses
Correct inset calculation
in FreeForm
Optimized reduction of lateral
unwanted astigmatism
• Due to the advanced eye lens system optimization the lens
minimizes the lateral unwanted astigmatim.
Optimized reduction of lateral
unwanted astigmatism in FreeForm
Lateral unwanted astigmatism
have been reduced also for
the human eye
Enhanced vision whatever the gaze
direction
Conventional lens SV
FreeForm individual SV
High vision performance in FreeForm
With FreeForm
Wider and clearer far also for
oblique gaze directions
Wider and clearer near
Conventional
High vision performance in FreeForm
Conventional PAL
FreeForm PAL
1. Wider and clearer far
2. Wider and clearer near
3. Optimized intermediate
4. Minimized lateral astigmatism
Personalization
• Personalization according to morphological parameters:
• Panto
• Wrap (ZTILT)
• Back Vertex Distance (BVD)
• Near Working Distance
• Pupillary Distances
• Frame Trace
Personalization
Average
personalization:
• FreeForm uses average
values for optimizing the final
lens to make easily the lens
ordering
Parameter
Label
P.D.
Vertex
Pantoscopic
Wrap
IPD
32 mm
BVD
14 mm
PANTO 12º
ZTILT 5 º
Average
value
Real data
personalization:
• Additionally to average
data, FreeForm optimizes the
lens using the real values of
each wearer for:
–
–
–
–
IPD – Inter-pupil distance
SEGHT
HBOX
VBOX
FreeForm Individual Power
Optimized for the wearer
Brand
FreeForm
Traditional progressive
İndividual progressive
User power
SPH: 3.25
CYL:1.50
AX:75
ADD:2.00
SPH: 3.25
CYL:1.50
AX:75
ADD:2.00
Lens meter power
Distance
SPH: 3.19
CYL:1.43
AX:62
Near:
SPH:5.10
CYL: 1.67
AX: 58
Base: 6.25
Index: 1.67
Prescribed power =
Measured power.
The final user will
perceive differences due
to the use position.
Base: 6.25
Index: 1.67
The final user will
perceive the
prescribed power.
Expected
power in the
lens meter.
Many thanks for
your attention !