7/15/2015 Spectacle Lens Update: Everything you need … · Spectacle Lens Update: Everything you...

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Spectacle Lens Update:Everything you need to know

Michael C. Vitale, ABOM, LDO, NCLCTechnical Director & Lens Division LiaisonThe Vision [email protected]

Michael Vitale has no financial interests to disclose

Click to edit Master title style

Impact of Good Vision

Average eyewear lifespan...> 28 months

Eyewear will be used for...> over 30,000 miles of driving> viewing 49 or more movies> 2.2 weddings / graduations> 26 family events & holidays> 1 in 3 presbyopes will see a

grandchild for the 1st time


Spectacle Lens UpdateHeader Example Goes here

Areas of Performance> Design> Surface> Filter> Substrate

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Spectacle Lens UpdateSingle Vision Lens Design

Historically> Spherical Lenses

» Corrective Curve Design- Optical Aberrations- Magnification for plus power lenses- Field of view Issues

> Steep curves» Difficulties fitting in todays flatter frame front designs


Spherical lenses create peripheral distortion because light is unequally refracted across the lens surface...

Spherical lenses create peripheral distortion because light is unequally refracted across the lens surface...

.......

multiple points of focusmultiple points of focus


Historically> Asphericity

» Reduces Optical Aberrations- Less magnification for plus power lenses- Less distortion- Increased field of view

> Cosmetically Flattens» Allows for flatter, thinner lenses

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Aspheric/Atoric lenses use multiple curvatures to reduce peripheral defocus and aberration.Aspheric/Atoric lenses use multiple curvatures to reduce peripheral defocus and aberration.

single focal pointsingle focal point


What’s New Now!

As Worn or Compensated Single Vision Lenses> The Rx is compensated to take into account the following

» Pantoscopic Tilt» Face form (Wrap Angle)» Vertex Distance

> Increases field of view> Less distortion

Products


Questions?Comments?

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Spectacle Lens UpdatePAL Lens Design

PALs Should Provide> Natural Reading Posture

» greater comfort while reading> Optimized Zone Placement

» ease of adaptation> Binocular Width

» wider intermediate vision> Sharp Distance Vision

» improved contrast at night> Specialized Design

» task/wearer specific zone distribution


Natural Reading PostureShorter progressions provide more natural reading postures...Shorter progressions provide more natural reading postures...

...a natural reading posture relies primarily on head movements...a natural reading posture relies primarily on head movements

Image courtesy of E

ssilor of Am

erica


Optimized Zone PlacementDistance Rx and ADD power determine optimal zone placement...Distance Rx and ADD power determine optimal zone placement...

...true multi-design PALs optimize zones for ametrops, for easier adaptation...true multi-design PALs optimize zones for ametrops, for easier adaptation

MYOPEMYOPEHYPEROPEHYPEROPE

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Binocular WidthThe ability to maintain fusion is called "binocularity" The ability to maintain fusion is called "binocularity"

...binocularity determines width- not the spherical area of the channel...binocularity determines width- not the spherical area of the channel

Image courtesy of E

ssilor of Am

erica


Binocular WidthPatented Design Technology allows specific alignment of astigmatism... Patented Design Technology allows specific alignment of astigmatism...

...this increases binocularity- and therefore intermediate width...this increases binocularity- and therefore intermediate width

Image courtesy of Essilor of America


Sharper Distance VisionNew Design Technology controls aberrations in the distance zoneNew Design Technology controls aberrations in the distance zone

...control of aberrations provides clinically proven gains in contrast...control of aberrations provides clinically proven gains in contrast

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Progressions can be designed specifically to a taskProgressions can be designed specifically to a task

STANDARD DISTRIBUTIONFAR DISTRIBUTION NEAR DISTRIBUTION

Specialized Design


Specialized DesignProgressions can be designed specifically to a frame typeProgressions can be designed specifically to a frame type

SHORT DISTRIBUTIONSTANDARD DISTRIBUTION


Specialized DesignProgressions can be designed specifically to an RxProgressions can be designed specifically to an Rx

OPTIMIZED ZONESSTANDARD DISTRIBUTION

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Specialized DesignProgressions can be designed specifically to a patient characteristicProgressions can be designed specifically to a patient characteristic

HEAD MOVEREYE MOVER STANDARD DISTRIBUTION

Spectacle Lens UpdateFitting & Dispensing

Products> Traditional & Freeform

» Thanks to the Lab Division of TVC

> Freeform» Thanks to Vision Care Product News

“Computer Glasses”?

“Task Specific”> Helps the eye adjust to intermediate-distance objects

such as computer screens» A modified lens power provides the consumer with a large

field of view» Too many products to mention, reference the Progressive

Lens Identifier

> Powerboost “single vision” lenses for non-presbyopes» Zeiss, Hoya, Essilor, etc.

> Over the counter products such as GUNNAR> Custom designed

» Double FT/Rd seg» Inverted» Golf seg

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Spectacle Lens UpdateFitting & Dispensing Proper fitting is crucial to the

performance of ANY and ALL designs> Proper adjustment of the frame

» Faceform» Pantoscopic Tilt» Vertex Distance

> Proper placement of the optics» Monocular PD’s» Monocular Fitting Heights

An improper fit will compromise the performance of ANY designFitting increases in importance with design complexity


Questions?Comments?

Spectacle Lens UpdateLens Surfaces

High Performance Surfaces Provide> Hardcoating – Thermal and UV

» greater durability> Multi-layer Anti-Reflective Stack

» sharper vision» increased night vision» better cosmetics

> Hydrophobic & Conductive Layers» easier to clean» greater durability

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Thermally-cured HardcoatThe lifespan of a lens is determined by the durability of the surfaceThe lifespan of a lens is determined by the durability of the surface

...surfaces are thermally bonded into the substrate...surfaces are thermally bonded into the substrate

SU

BS

TR

AT

EPrimerPrimer

Silica-Resin HardcoatSilica-Resin Hardcoat


Multi-Layer AR StackSurfaces include a multi-layer AR for increased transmissionSurfaces include a multi-layer AR for increased transmission

...AR also reduces night-time reflections/glare and provides superior cosmetics...AR also reduces night-time reflections/glare and provides superior cosmetics

SU

BS

TR

AT

E

Multi-Layer AR


Hydrophobic & Conductive Layers

An AR incorporating a TCO (transparent conductive oxide) will repel dust and other particlesAn AR incorporating a TCO (transparent conductive oxide) will repel dust and other particles

...a hydrophobic layer repels water & oil-resulting easier and less frequent cleaning...a hydrophobic layer repels water & oil-resulting easier and less frequent cleaning

SU

BS

TR

AT

E

Hydrophobic Layer

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Hydrophobic & Conductive LayersHydrophobic durability is a function of coating density...Hydrophobic durability is a function of coating density...

...higher densities lead to a longer effective hydrophobic lifespan...higher densities lead to a longer effective hydrophobic lifespan

Imag

e co

urte

sy o

f Ess

ilor

of A

mer

ica


Include high-performance surfaces on your lenses> Nearly all patients want:

» Increased visual acuity» better night vision» increased durability» ease of cleaning» less noticeable eyewear

60% of all US eyewear consumers choose AR when informed of its benefits


Questions?Comments?

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Spectacle Lens UpdateLens Filters

Lens Filters> UV Filters> Photochromic’s

» adjustable filtering» UV protection

> Polarized» glare reduction» superior contrast» sport & vocational applications» UV protection

> Fixed Tint» neutral & selective filters

> Specialized Filters/AR Coatings» Selectively filters blue light and UV

Ultraviolet Filters> There are 3 types of UV

» UVC < 285nm» UVB 286 – 320nm» UVA 320 – 380nm

» HEV > 380nm

Only 2 materials do not block UV» clear CR-39» clear glass


ozon

e


Ultraviolet Filters> On average, 80% of UV exposure will occur

prior to age 20

100% UV protection is a standard-of-care requirement for all children> Polycarbonate or Trivex> brimmed hats> sunscreen

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Photochromic lenses provide> Comfortable vision in nearly all lighting conditions

> Complete protection from UV

Image courtesy of Transitions


Polarized Filters provide> reduction of glare

» reflections from flat surfaces are reduced or eliminated

> increased contrast sensitivity» selective filtering of glare

> sport & vocational applications» watersports» driving


Reduction of glare

Non-polarized light contains energy along all axes along its directionNon-polarized light contains energy along all axes along its direction

...a polarizing filter polarizes light along a single axis...a polarizing filter polarizes light along a single axis

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Reduction of glare

When light hits a smooth transparent surface, polarization occursWhen light hits a smooth transparent surface, polarization occurs

...water causes horizontal polarization...water causes horizontal polarization


Increased contrast sensitivityNon-polarizing filters attenuate light non-selectively, reducing contrastNon-polarizing filters attenuate light non-selectively, reducing contrast


Increased contrast sensitivity

Polarizing filters preserve contrast by selectively filtering glarePolarizing filters preserve contrast by selectively filtering glare

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Polarized applications - drivingPolarized lenses increase contrast perception & decrease reaction timesPolarized lenses increase contrast perception & decrease reaction times


Polarized applications - drivingPolarized lenses increase contrast perception & decreases reaction timesPolarized lenses increase contrast perception & decreases reaction times

20/100

20/80

20/63

20/50

20/40

20/32

20/25

20/20

20/15

20/10

1.0 10.0 100.0

Contrast

Sn

elle

n V

A

Tinted AR

Polarized AR

Neutral & Selective FiltersNeutral (grey) filters attenuate light evenly across the spectrum- selective filters may improve contrast

Neutral (grey) filters attenuate light evenly across the spectrum- selective filters may improve contrast

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Objective of FiltersFilter out harmful / distracting light

• UV and/or IR• reflected glare

Transmit useful light• preserve contrast• manipulate color perception

– preserve color perception (neutral grey)– alter color perception (all other colors)


ALL filters (except UV and AR) reduce light transmission

(including "contrast enhancing" night driving lenses)


Specialty Filters / AR CoatingsFilter HEV “Blue” Light

UV and/or Blue LightReflected glare

Transmits 97.5% lightReduces eye fatigue when using computers, iPads/Tablets and mobile devices

ZEISS DuraVision BlueProtect

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Questions?Comments?

Spectacle Lens UpdateSubstrates (Lens Materials)

Premium Substrates Provide> Safety

» Impact Resistance» UV Protection

> Structural Durability» High Tensile Strength (drill mounts)

> Superior Cosmetics» Thin Profile» Optical Clarity

> Superior Comfort» Light Weight


Safety> Polycarbonate is the only material that retains a constant

level of impact resistance in all forms> Polycarbonate resists extreme impact level with any surface

UNCOATED HC SURFACE AR SURFACE

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Safety> All materials MUST pass the FDA drop-ball test

» (Federal Law)> Hard coating and AR coating will greatly reduce impact

resistance

UNCOATED HC SURFACE AR SURFACE


Structural Durability> Tensile strength is a measure of a materials ability to resist

“tearing”» This equates into resistance to splitting in drill mounts

Tensile Strength By Material» 80.5 kg/f = 1.60 (MR8)

» 70 kg/f = 1.67 (MR10)-Approx.

» 67.3 kg/f = 1.67 (MR7)

» 61.2 kg/f = Trivex

» 52.9 kg/f = 1.70

» 44.9 kg/f = polycarbonate

» 15.6 kg/f = CR-39

80kg


Superior Cosmetics> High Index Lenses Reduce Thickness

1.501.601.74

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Superior Cosmetics> Optical Clarity Is A Function Of

» Transmittance

- Perception of white target» Color Rendering

- Perception of chromatic target

» Contrast- Ability to perceive contrast near and far

> Abbe is not a major function of clarity» The eye has approximately 1.00D of linear chromatic

aberration (which does not impair vision)- (-10.00D poly lens viewed at 30° produces <0.50D of linear

chromatic aberration)

Spectacle Lens UpdateDispensing

Recommending Substrates> Polycarbonate for Safety

» Children (Trivex is also a good option)» Monocular patients» Most safety applications

> Tensile strength for drill mounts» 1.60, 1.67» Trivex» Polycarbonate

> Higher Index for Thinness» 1.60, 1.67, 1.70, 1.74

> Low Specific Gravity for Lightness» Polycarbonate» Trivex

Spectacle Lens Update Dispensing

Summary> Design

» Binocularity = Width» Reduced aberration = Contrast sensitivity» Customization = Potential for greater performance

> Coatings» Thermal cure = permanent adhesion» AR Coating = Better Vision and Greatly Improved Cosmetics

- Conductive Layer = anti-static- Dissymmetric = hydrophobic

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Spectacle Lens UpdateDispensing

Summary> Filters

» UV» Photochromic's» Polarized» Fixed Tints

> Substrates» Polycarbonate for Safety (Trivex)» High Index

- Great for Drill Mounts


Questions?Comments?

Special Thanks toPete Hanlin, Technical Director

Essilor of America, Inc.

Michael C. Vitale, ABOM, LDO, NCLCTechnical Director & Lens Division LiaisonThe Vision [email protected]

Special thanks to

7/15/2015 Spectacle Lens Update: Everything you need … · Spectacle Lens Update: Everything you...

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