TIPS NO: 256
Revision: B
Date: August 17, 2007

KODAK Precise Short™ Progressive Lenses in
Standard Resin Product Specifications and Fitting Guide.

PURPOSE: The following information will assist you in processing KODAK Precise Short Lenses in scratch resistant coated and uncoated standard resin.

SUMMARY OF CHANGES: Characteristics Table and Base Curve Selection Chart have been changed.

Characteristics	KODAK Precise Short Lens
Refractive Index	1.498 ref d
Dispersion Value (Abbe)	58.0
Density	1.32
UV Transmission Cutoff	355
Chemical Resistance	Excellent
Machinability	Excellent
Rear Surface Coating	Optional
Scratch Resistant	In-Mold RLXPlus®

UNIQUE SEMI-VISIBLE MARK: K_S
BLANK SIZE: 74mm diameter blanks decentered 3mm. Effective diameter is 80mm.
BASE CURVES: 2.00, 4.50, 5.50, 7.50
POWER RANGE: -10.00 TO +5.00
ADD RANGE: 1.00 to 3.00 in .25 Diopter steps.
THICKNESSES: We recommend a minimum center thickness of 2.0mm, or 2.2mm if AR coated.

KODAK Precise Short Progressive Lens in standard resin - DIMENSIONS

Nominal Curve	True Curve	Radius mm	SAG at 50mm	Nominal Concave	Edge Thickness	Center Thickness
2.00	2.02	262.376	1.19	3.00	13.9	13.6
4.50	4.54	116.740	2.71	6.00	10.8	9.6
5.50	5.58	94.982	3.35	6.00	7.2	7.5
7.50	7.63	69.463	4.65	6.00	7.1	10.6

GENERAL:
Processes used for surfacing CR39® lenses should be applied to KODAK Precise Short Lenses. 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 Short 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 Short Lens markings have a “+” at the nasal and temporal sides along the 180º axis line. Approximately 3mm below the nasal “+” you will find the “KS” 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/REMARKING THE TEMPORARY REFERENCE MARKS:
The KODAK Precise Short Lens markings provide an easy way to verify the edging accuracy and must be removed before tinting. These marks are designed to withstand all processing procedures. They may be removed by wiping the surface with alcohol or other standard resin 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, dot them on the lens and use the KODAK Precise Short verification chart for the final re-marking.

AR COATING:
Because lens impact resistance is reduced by AR coatings, we recommend conducting impact tests 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:
The KODAK Precise Short Lenses in scratch resistant coated standard resin tint and neutralize as other RLXPlus lenses using normal materials and methods. The temporary lens markings used must be removed prior to tinting. The tinted lens should be cleaned with alcohol or acetone to remove excess dye from the surfaces.

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 13 mm. The frame shape, frame PD and patient’s PD affect how much of the full addition reading area falls inside the frame. To ensure these variables will not limit near vision, lay the frame (with the fit point marked) onto the KODAK Precise Short Lens Dispensing Aid (part number 357-893). 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. Precise Short is a trademark and RLXPlus is a registered trademark of Signet Armorlite, Inc. CR39 is a trademark of PPG.