Customization of Ophthalmic Lenses Manel EspĂnola INDO Lens Group II Spanish Optical Design Meeting October 2013
Index Introduction to INDO Lens design Aberrations Single vision lenses Progressive Addition lenses Free Form Surface Design
Summary & Future Made 4 u
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
INDO 430 Employees Lenses and Equipment Goods Offices and Laboratory (Capacity 5000 lens/day)
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
INDO: R&D 1972: Set up of Indo’s R&D department INDO invests 3.5% of its turnover in R&D and innovation. 80% of sales corresponds to products launched in the last three years. 18 people (including 8 PhDs) work on different areas of R&D : chemistry, physics, optics, industrial engineering, telecommunications, etc.
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
INDO: R&D
R&D Groups and Optics Thin Films
Lens Design
Prototypes and Metrology
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Index Introduction to INDO Lens design Aberrations Single vision lenses Progressive Addition lenses Free Form Surface Design
Summary & Future Made 4 u
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Lens Design: Monochromatic Aberrations Zernike Decomposition
Rx prescription
Secondary errors
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Lens Design: Minimizing Chromatic Aberrations Use materials with high Abbe values.
Use well-centered and properly fitted frames.
Use the correct base curve or lens design. Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Lens Design : Base curve selection Oblique astigmatism: light refracted differently by the tangential and sagittal meridians of the lens
1904: Tscherning ellipses: Two recommended best form curves for lens power Theoretically
Reality
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Index Introduction to INDO Lens design Aberrations Single vision lenses Progressive Addition lenses Free Form Surface Design
Summary & Future Made 4 u
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Lens Design: Single Vision Lenses
Historical: Conventional lenses Moulds and simpler surfaces Lensmaker equation
1990’s - Free Form Technology Free Surface Design Higher precision Greater field of view Less aberrations Stock of blanks
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Lens Design: Optical behavior on SV Lenses Conventional lenses provides poor optical behavior, specially for high prescriptions SPH. +6 D.
Oblique astigmatism at 30째. CYL. +6 D.
A.O= 0 - 0.24D A.O. = 0.25D - 0.49D A.O. = 0.50 - 0.74D A.O= > 0.75 D
-12 D.
Grouped base curves limits optical behavior for single vision lens, even using aspherical back surfaces since they are optimized for a single lens of the group. SPH. +6 D. CYL. +6 D.
-12 D.
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Lens Design: As worn position
Importance of as worn position
y
Nasopupilar distance Fitting height Lens tilts Vertex distance Additional parameters
V.
e of Angl
H. Ang le
n visio
of visio n
6.40 D.
6.15 D.
V. Angle of vision (°)
V. Angle of vision (°)
V. Angle of vision (°)
H. Angle of vision (°)
SPH = +6 D. 10° vertical tilt, 5° horizontal tilt
SPH = +6 D. 10° vertical tilt
SPH = +6 D. No tilts
x
H. Angle of vision (°)
H. Angle of vision (°)
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Lens Design: New Proposal for SV Lenses (Patent:P201132048) Proposal: Hyperbolic term
Exponential term
f ( x, y ) = a1 + a2 1 − a3 x 2 − a4 y 2 + a5 exp(a6 x 4 + a7 y 4 + a8 x 2 y 2 ) Optimized under a merit function Spherical Lens aberrations
and optical constrains Optimized aberrations FC
AOV(°) 30°
FC
AOV(°) 30°
OA
OA
OPTIMIZATION 15°
-0.5
0 0.5 Error (D.)
f .m. = f .m.(α , OA, FC )
15°
0 0.5 Error (D.) Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona -0.5
Lens Design: New Proposal for SV Lenses (Patent:P201132048) Example of oblique astigmatism optimization:
f .m. = f .m.(α = 30°, AOE )
f ( x, y ) = a1 + a2 1 − a3 x 2 − a4 y 2 + a5 exp(a6 x 4 + a7 y 4 + a8 x 2 y 2 ) a6
SPH SPH
SPH
SPH Spherical
Proposal
SPH: -2.0 D.
H. Angle of vision (°)
Proposal
V. Angle of vision (°)
V. Angle of vision (°)
H. Angle of vision (°)
a8
V. Angle of vision (°)
SPH: 8.0 D. V. Angle of vision (°)
Spherical
a5
H. Angle of vision (°)
H. Angle of vision (°)
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Lens Design: New Proposal for SV Lenses (Patent:P201132048)
f ( x, y ) = a1 + a2 1 − a3 x 2 − a4 y 2 + a5 exp(a6 x 4 + a7 y 4 + a8 x 2 y 2 ) Features General 2D surface Independent from base curve Sphere and aspheres as particular cases, in general, different from both cases Results depending on variables inside merit function
SPH. +6 D.
SPH. +6 D.
Oblique astigmatism at 30°. CYL. +6 D.
CYL. +6 D.
A.O= 0 - 0.24D A.O. = 0.25D - 0.49D A.O. = 0.50 - 0.74D A.O= > 0.75 D
-12 D.
-12 D. Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Index Introduction to INDO Lens design Aberrations Single vision lenses Progressive Addition lenses Free Form Surface Design
Summary & Future Made 4 u
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Lens Design: Progressive Addition Lenses Presbyopia is a condition where, with age, the eye exhibits a progressively diminished ability to focus on near objects Non avoidable Around 40 years Need of additional power Single Vision
Bifocal
Multifocal
1953 – B. Maitenaz patented the first multifocal lens (Varilux) Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Lens Design: Progressive Addition Lenses Progressive addition lenses provides continuos power variation across the lens
Minkwitz Theorem: unwanted astigmatism
∂Cyl ∂Add ≈2 ∂y ∂x
y
1
2
NEAR
INTERMEDIATE
DISTANCE
Addition (D.)
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Lens Design: Progressive Addition Lenses Minkwitz: Shorter progressions increases unwanted astigmatism.
Y (mm.)
Addition (D.) 1 2
Depending on the progression’s length, astigmatism at corridor is fixed, but not in the surroundings. Soft Design
Hard Design
Variable aberrations distributions
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Lens Design: Progressive Addition Lenses
Importance of as worn position and visual behavior Visual Map Developer Patent:WO2005/107576 A1
Head movers
Eye movers
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Lens Design: PAL Design (Patent: WO2005/109082 A1) Lens Design Wearer parameters (Rx, IPD, AWP,‌) Manufacturing parameters PAL Design (Hard, Soft,‌)
1. Optimization of virtual lens
2. Composition Equivalent lens
Optimization of optical properties
3. Additional Surface Design
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Lens Design: PAL Optimization Virtual Lens Optimization: PAL Front surface + Rx Back Surface OPTIMIZATION VARIABLES
MERIT FUNCTION n
min
n
r
r
∑ α i (asti ( x ) − astNomi ) 2 + ∑ β j ( pot j ( x ) − potNom j ) 2 i =0
r j =0 potNomk − tolPot k ≤ pot k ( x ) ≤ potNomk + tolPot k k = 0...n subject to 2 r astl2 ( x ) ≤ astNoml + tolAstl l = 0...n
(
NO
)
¿OK? YES Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Lens Design: PAL Optimization (Patent: US 2013/0114040 A1) Virtual Lens Optimization: Versatile and powerful Plano Ad 3. Unwanted cylinder isolines 0.5 D.
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Lens Design: PAL Composition method Advantages Fast and versatile Able to mix different types of surface Takes into account manufacturing parameters
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Index Introduction to INDO Lens design Aberrations Single vision lenses Progressive Addition lenses Free Form Surface Design
Summary & Future Made 4 u
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Lens Design: Free Form Surface Design Free Form CNC Cutting Technology
Free Designs, fewer and weaker constrains
Enhanced Optical Design capabilities!! Aberrations optimization Thickness reduction
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Lens Design: Free Form Surface Design (Patent: P200900849) Plus Lens cross section z SCC
Etmin
This manufacturing limit determines the minimum Center Thicknes of the lens
SCX
Ctmin
x
rblank
How can we thinner a plus lens restricted by a minimum edge thickness? Now it is possible to modify original surface out of the frame!
z
SCC
Transition zone
Etmin
SCC
SCX
Ctmin rframe
z
Inside Frame Lens
x
Etmin SCX
Ctmin rframe
x
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Lens Design: Free Form Surface Design (Patent: P200900849) Great thickness advantages Plus Lenses (up to 60% decrease in Center Thickness)
Frame size
Minus Lenses (Gain in Edge Thickness)
Frame size
Designs not so Free‌ There are Free Form cutting Limitations Surface Curvature (D.)
Zones with high curvature values
Cutting errors Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Index Introduction to INDO Lens design Aberrations Single vision lenses Progressive Addition lenses Free Form Surface Design
Summary & Future Made 4 u Optician 20/20
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Summary and Future
Ophthalmic Lenses has suffered a great advance with Free Form cutting Technology Lens Design has become more important since it is possible to cut the desired surface with high precision Due to versatile Lens Design it is possible to consider different wearing and users factors (AWP, frame size, aesthetics‌) for optimize vision and user’s benefits Market demands customization on lenses and frames European projects: MADE4u and Optician 2020
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Summary and Future Customization
Lens
Optical Design
Manufacturing
Frame
Coatings
Color
Size
Polish
Decoration
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Summary and Future Customization of lenses and frames Measuring device for optometric measures
Rapid prototyping for frames manufacturing
Spanish Optical Design Meeting -October 2013 UPC Campus Nord - Barcelona
Thank you!