TIPS NO

 

241

Revision

 

 

Date:

 

May 2004

 

 

 

 

 

Kodak Concise™ Progressive InstaShades™ Gray and Brown
1.6 EvoClear® Lens
Product Specifications and Fitting Guide.

 

Purpose:
The following information will assist you in processing Kodak Concise Progressive InstaShades 1.6 EvoClear Lenses.

 

Characteristics

KODAK Concise InstaShades 1.6 EvoClear Lens

Refractive Index

1.594

Dispersion Value (Abbe)

32.0

Density

1.34

Chemical Resistance

Excellent

Machinability

Excellent

Rear Surface Coating

Required

Scratch Resistant

In-Mold RLXPlus®

UV Blocking

100% of UV A and UV B

 

Unique Semi-Visible Mark:

Kc6

Blank Size:

72mm diameter blanks decentered 3mm

Effective diameter is 78.

Base Curves:

 0.50, 1.25, 3.25, 5.50, 7.50

Power range:

Sphere-10.00 to +6.00, Cylinder to -5.00

Add range:

1.00  to 3.00 in .25 Diopter steps

Thicknesses:

We recommend a minimum center thickness of 1.6mm, or 1.8mm if AR coated, and a minimum edge thickness of 1.4mm.

Be sure to add your tolerance to these values for Rx calculation.

 

InstaShades lenses are a MultiMatrix™ product.  The photochromic materials are contained in approximately the front 1.0mm of the lens.  The material behind the first 1.0mm provides the optical properties.  The mechanical properties of the lenses depend on the all of the elements of the MultiMatrix design.  Therefore, it is important to surface the lenses to meet or exceed the recommended minimum center or edge thicknesses.
 

 


KODAK Concise Progressive InstaShades 1.6 EvoClear Lens - Dimensions

 

General:

These high index lenses have a refractive index of 1.594.  Standard pads and polish materials used for surfacing CR-39® lenses are suitable for EvoClear Lenses.  If you have questions, please contact Technical Services at 800-759-0075.

 

Computer Calculation of Rx:

The easiest, most efficient method to calculate and process values for an Rx is to use an existing computer software package that contains KODAK Concise Lens design data.   If your software company has not included this data in its package, our Technical Services group will be happy to provide the necessary specifications.  Please forward us the contact name and phone number of your software vendor.  If you need a software program for processing lenses, Signet Armorlite has developed a computer program to calculate surfacing data. This program is available through Signet Armorlite's Technical Services Department.

 

Abrasion Resistance Coatings:

The front surface has the superior protection of the RLXPlus non-tintable coating. Since the uncoated rear surface of the lens will likely not provide adequate durability for normal use, backside coating is recommended. Applying a backside coating after surfacing is required when the lens will be anti-reflective coated.  Be sure to verify that impact resistance is maintained, particularly when using a non-tintable coating. Please call Technical Services for the latest test results with various backside coatings.


Layout:

All surfacing should be done in relation to the prism reference point located on the 180º axis.  We recommend that you block the lens on the prism reference point even though the corridor is decentered 3 mm. If blocking is done on the geometric center of the blank, you must calculate the amount of decentration prism needed to move the optical center to the prism reference point.  The fitting cross is located 2.0mm directly above the prism reference point dot.  If you use an automated lens blocker, such as the Gerber Step-One System, and if you are blocking on the cross, be sure to use a segment placement on the lens blank of
-2mm down (2 up), 2.7mm in.

 

Semi-Visible Markings:

Kodak Concise Lens markings have a “+” at the nasal and temporal sides along the 180º axis line. Approximately 3mm below the nasal “+” you will find the “Kc6” product code.  Approximately 3mm below the temporal “+” you will find the add power of the lens.  These marks can be located by visually inspecting the lens.  Position the lens at arm's length, preferably in front of an overhead fluorescent light.  Slowly move the lens away from the edge of the light fixture while looking at the estimated location of the marks along the surface of the lens.  The marks will become visible at a given angle of light.

 

Removal/Re-marking the Temporary Reference Marks:

The KODAK Concise Lens markings may be removed by wiping the surface with alcohol, acetone, or standard lens mark removing solvents.  These marks are designed to withstand all processing procedures.  They provide an easy way to verify the edging accuracy and can be removed before or after tinting.

 

To re-mark the lens, first locate the semi-visible markings, specifically the “+” symbols engraved along the 180º axis line (see above procedure for locating the semi-visible marks).  Once you have located the semi-visible markings, dot them on the lens and use the KODAK Concise verification chart for the final re-marking.

 

Special Requirements:

The KODAK Concise InstaShades 1.6 EvoClear Lens processes much like our 1.56 high index and CR-39 lenses.

 

When cribbing while generating, use a cycle that leaves a smooth edge. Leaving fractured or rough edges can lead to cracked lenses.  Lathe style generators may need a slower rough cycle or deeper finish cut to remove subsurface fractures.

 

ONE-STEP Fining Pads

Millimeter Take-off @ 20 sec. intervals

Pad Brand & Type

20

40

60

80

PSI P-1000

0.17

0.32

0.45

0.56

DAC Fire (Fine red vinyl) & SALEM 933

0.15

0.25

0.37

0.46

SALEM Wizard 825

0.25

0.46

0.66

0.85

TWO-STEP Fining Pads (DAC)

 

Pad Brand & Type

20

40

60

80

1st Fine:   600 GRIT

0.18

0.30

0.42

0.52

2nd Fine:  9 MICRON BLUE

0.02

0.05

0.08

0.11

1st Fine:  SALEM 983

0.17

0.33

0.49

0.64

2nd Fine:  SALEM 1128

0.06

0.09

0.12

0.13

 

POLISHING TIME ( 2 minutes)

Allow  0.1mm Take-Off

 

Fining and Polishing:

Processing the 1.6 EvoClear Lens is similar to the CR-39 lens material. Safety bevel the lens before fining to alleviate chips and allow the slurry smoother access along the lens surface. Large lap tools (at least 3 inch) should be used and allowance made for approximately 0.3mm of stock removal.  We strongly recommend fining pads with eight or more petals be used for curves over 9.00 diopters.  This can prevent swirls caused by wrinkles in the pads which can result in an aberrated lens.  Should you experience unusual reject causes, retain samples and contact Technical Services for assistance.

 

Edging:

Layout for edging should be done in reference to the fitting cross located 2.0mm above the MRP. The fitting cross is placed at the point of the specified segment height and monocular PD.

 

Drilling:

InstaShades lenses have been successfully used on three-piece frames that require drilling or slotting.  Many variables will contribute to successful three-piece frame usage.  They include machining, smooth surfaces, chamfering the edges, using grommets to cushion the contact, not over-tightening the screws, and patient care.

 

SignetArmorlite recommends using lens materials with superior strength such as polycarbonate for three-piece frames.

 

AR Coating:

Multi-layer AR coatings can be applied to KODAK Concise InstaShades Lenses. Because lens impact resistance is reduced by AR coatings, we recommend a 1.8mm minimum center thickness and a backside coating that will enhance the impact resistance capability.  This minimum thickness recommendation is based on surfacing to no less than 1.8 mm and using UltraOptics UVNV backside coating prior to applying AR coating.  Other back surface coatings may enhance or reduce the impact resistance.

 

Be sure that your AR and backside coatings are compatible.  If you have lenses AR coated by a coating service, include such samples in your impact testing.   It may be necessary to increase the minimum center thickness in order to meet impact resistance requirements.  Please call Technical Services at 800-759-0075 for additional information about coatings and impact resistance.

 

Tinting:

We do not recommend tinting InstaShades lenses.  Doing so will void any factory warranty.

 

Thermal Stability:

KODAK Concise InstaShades 1.6 EvoClear Lens material has a similar level of heat sensitivity as other 1.6 high index materials.  The lens will flex if heated under pressure.  To prevent warpage, avoid heating the lens over 130ºF while under pressure from the frame or clamping during coating.  Warpage can cause a plastic lens to become loose in the frame.  If the lens should become warped, heat without pressure to allow the lens to return to its original shape.

 

Call Technical Services for more processing information or technical data.  Current customers can find information and TIPS on Signet Armorlite products by visiting our web site at www.signetarmorlite.com.

 

Fitting and Frame Selection:

We recommend a fitting height (sometimes called the segment height) of 17mm, based on the 12mm corridor length.  The measurement includes 2mm above the reference dot where the fitting cross is marked, as well as 3mm of clear area below the full addition location.  Minimum fitting height values are completely Rx and frame dependent. The frame shape and patient’s monocular PDs will affect this minimum fitting height, which is measured from the lowest point of the frame and not the lowest point of the frame where the reading area falls. Illustration 1.0 shows that the near zone may not fall inside the frame for certain frame and monocular PD requirements.

 

The simplest and most accurate way to ensure that an adequate distance and near area will be enclosed within the frame is to use the KODAK Concise center/sizing chart.  Mark each fit point on the demonstration lenses in the frame and lay it over the center/sizing chart to verify that the critical optical zones fall within the eye wire.

 

If a small portion of the critical optical area is outside the frame, discuss with the patient the optical compromise that will occur if this frame is used.

 

Illustration 1.0
 

 
 

 

 


                    Fit Point                                                                                               Fit Point

 

 

 

 

 

 

 

 

 

Usable full addition point inside frame   

Unusable full addition point out of frame

 

Kodak is a trademark of Eastman Kodak Company, used under license by Signet Armorlite, Inc.

RLXPlus and EvoClear are registered trademarks, MultiMatrix, Concise and InstaShades are trademarks of Signet Armorlite, Inc.

CR-39 is a registered trademark of PPG.