TIPS NO

 

250

Revision

 

 

Date:

 

May 2006

 

 

 

 

 

Kodak Precise™ Progressive TLX1.6™ Lens
Product Specifications and Fitting Guide.

 

Purpose:
The following information will assist you in processing Kodak Precise Progressive  TLX1.6 Lenses.

 

Characteristics

KODAK Precise TLX1.6 Lens

Refractive Index

1.594

Dispersion Value (Abbe)

42.0

Density

1.30

Chemical Resistance

Excellent

Machinability

Excellent

Rear Surface Coating

Required

Scratch Resistant

Front side coated

 

Unique Semi-Visible Mark:               K+à

 

Blank Size:            74mm & 78mm diameter blanks decentered 3mm

Effective diameters are 80 and 84mm, respectively.

 

Base Curves:         0.50, 1.50, 3.25, 5.00, 7.00, 8.50

 

Power range:-10.00 to +7.50

Add range:            1.00  to 3.00 in .25 Diopter steps.

 

Thicknesses:        We recommend a minimum center thickness of 1.5mm,

or 1.7mm if AR coated.

 

KODAK Precise Progressive TLX1.6 Lens - Dimensions

Nominal Curve

Diameter

True Curve

Radius mm

SAG at 50mm

Nominal Concave

Edge Thickness

Center Thickness

0.50

74

0.59

898.305

0.35

6.00

16.2

7.3

1.50

74

1.48

358.108

0.87

6.00

15.9

7.3

3.25

78

3.20

165.625

1.90

6.00

16.4

7.3

5.00

78

5.24

101.145

3.14

6.00

14.1

7.2

7.00

78

7.05

75.177

4.28

6.00

6.9

9.4

8.50

74

8.62

61.485

5.31

6.00

7.3

10.7

 

General:

Surfacing procedures for standard resin progressive lenses should be used with the Kodak Precise TLX1.6 Lens, but bear in mind that TLX1.6 has a refractive index of 1.594.  If you have questions regarding these lenses, 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 Precise 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.

 

Layout:

All surfacing should be done in relation to the prism reference point located on the 180° line.  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 directly above the prism reference point dot.  This improves the accuracy of positioning the patient's pupil to the center of the corridor.  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 4mm down.

 

Semi-Visible Markings:

Kodak Precise Lens markings have a “+” at the nasal and temporal sides along the 180º axis line. Approximately 3mm below the nasal “+” you will find the “K+à” 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 Precise Lens marks are designed to withstand all processing procedures.  They provide an easy way to verify the edging accuracy.  The markings may be removed by wiping the surface with alcohol or other standard lens mark removing solvents.

 

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 use a felt pen to mark a spot over the “+” symbols, and trace the progressive markings using the KODAK Precise Lens Verification Mask or the Center/Sizing chart.  Use the fitting cross to accurately optimize optics during final fitting of KODAK Precise TLX1.6 Lenses.

 

Fining and Polishing:

Processing the TLX1.6 Lens is similar to standard resin 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 flares and wrinkles.

 

Abrasion-Resistant Coatings:

The front surface has the protection of a non-tintable anti-scratch coating. Signet Armorlite recommends using either a tintable or non-tintable backside coating after surfacing. Verify that the impact resistance is maintained, particularly when using a non-tintable coating.

 

Impact Resistance:

Our test results indicate that lenses backside coated with UVX by Ultra Optics, UVNVS by Ultra Optics, or HT1000 by Gerber Coburn exceed the FDA impact-resistance requirements and are 100% compatible with the KODAK Precise TLX1.6 Lens.  Contact our Technical Service Department if you are using a different coating.

 

Edging:

Layout for edging should be done in reference to the fitting cross located 4.0mm above the MRP. The fitting cross is placed at the point of the specified segment height and monocular PD.

 

AR Coating:

Multi-layer AR coatings can be applied to Kodak Precise Lenses. Because lens impact resistance is reduced by AR coatings, we recommend a 1.7mm minimum center thickness and a backside coating that will enhance the impact resistance capability.  Be sure that your AR coating is compatible with your backside coating.  Include impact testing for lenses AR coated and sold by your lab.   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:

To achieve a gray tint the lens color can be adjusted with G-15 green dye. The resin naturally absorbs more blue which requires compensation in other colors. Special 1.6 high index tints are available from most tint supply companies.  When a tintable backside coating is used, tint performance and compatibility with specific neutralizers are coating dependent.

 

Neutralizing:

After neutralizing the TLX1.6 lenses, you may see surface irregularities.  If the lenses are being retinted a different shade, these surface irregularities will disappear while tinting.  If the lenses will not be retinted, warm the lens with dry heat from a lamp or oven for 10 to 30 minutes to remove the irregularities caused by neutralizer.

 

Always limit the exposure to neutralizer to 20 minutes at 200 degrees.

 

Thermal Stability:

KODAK Precise TLX1.6 Lenses may warp while under pressure when exposed to temperatures over 150°F.  Warpage can cause a plastic lens to become loose in the frame.  If the lens should become warped beyond tolerance, place the lens on a flat tray in a oven at 200°F for approximately 5 minutes or until the lens is heated all the way through, causing it to relax to its original shape.

 

Fitting and Frame selection:

The fitting point (+) has been positioned slightly higher than our other progressives. Therefore, you can fit the lens at the center of the pupil rather than at the bottom of the pupil. Always use monocular PDs and individual fitting heights when they differ more than 1.0 mm.

 

We recommend a minimum fitting height (sometimes called the segment height) of 20 mm. While a successful fitting of Precise lenses is possible with less than a 20 mm fitting height, we recommend the KODAK Concise™ short corridor lens for smaller fitting height situations.

 

The frame shape, frame PD and patient’s PD affect how much of the full addition reading area falls inside the frame. To insure these variables will not limit near vision, lay the frame (with the fit point marked) onto the KODAK Lens Dispensing Aid (part number K763-578.)  Check to see if the blue shaded area is contained within each eye of the frame. This chart also references a recommended minimum distance up from the fitting point to the frame edge. We advise a minimum distance viewing area of approximately 12mm for patient comfort.

 

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

Concise, Precise and TLX16 are trademarks of Signet Armorlite, Inc.


KODAK Precise Lens in TLX1.6

Base Curve Selection Chart