TIPS 197I SunSensors

TIPS NO

197

Revision

I

Date:

July 2002

Signet Armorlite Navigator^™ Progressive
Single Vision and Flat Top Lenses with
SunSensors^® by Corning^® (Gray & Brown^*)
Lens Product Specification & Processing Information

Purpose:
The following information will assist you in processing the SUNSENSORS Navigator Progressive, Single Vision, and Flat-Top lenses.

Summary of TIPS version changes:
This TIPS revision incorporates the stabilized SunSensors material which is identifiable by the letter "S" following the SunSensors name in technical files, includes a title change, lay-out information, temporary marking removal instructions, semi-visible marking information, a cold weather use advisory, and drilling instructions.

Characteristics & Dimensions

*Characteristics*	SunSensors by Corning
Refractive Index	1.555
Dispersion Value (Abbe)	38
Density	1.168
RLXPlus^® Scratch Resistance	Non-Tintable Front Surface

Signet Armorlite Progressive Dimensions
Blank Size: 76mm diameter

Base Curves: 0.50, 2.00, 4.50, 5.75, 7.75
Power Range: -13.00 to +6.00
Inset: 2.5mm
Add Powers: 1.00 to 3.00 in 0.25 Diopter Steps

Nominal Curve	True Curve	Radius mm	SAG at 50mm	Nominal Concave	Edge Thickness	Center Thickness
0.50	0.56			3.0	16.0	12.7
2.00	1.96			6.0	16.5	9.4
4.50	4.58			6.0	10.5	7.4
5.75	5.84			6.0	7.0	6.9
7.75	7.87			6.0	7.0	10.5

Single Vision, and Flat-Top 28, Flat-Top 35, and 7 X 28 Dimensions
Blank Size: 74mm diameter and 70mm (SV only) diameters

Base Curves: 0.50, 2.00, 4.12, 6.12, 8.50
(0.50 not available in Trifocals)
Power Range: -13.00 to +6.00
Add Powers: 1.00 to 3.00 in 0.25 Diopter Steps
      1.50 to 3.00 in 0.25 Diopter Steps for Trifocals
Flat-Top Inset:
    Bifocal: 5.0mm in, 5.0mm down
    Trifocal: 5mm in, 4.0mm down

70mm lens data

Nominal Curve	True Curve	Radius mm	SAG at 50mm	Nominal Concave	Edge Thickness	Center Thickness
0.50	0.45			3.0	15.1	12.2
2.00	1.91			6.0	12.4	7.5
4.12	4.02			6.0	9.6	6.9
6.12	6.01			6.0	5.7	5.8
8.50	8.45			6.0	4.1	7.3

74mm lens data

Nominal Curve	True Curve	Radius mm	SAG at 50mm	Nominal Concave	Edge Thickness	Center Thickness
0.50	0.45			3.0	16.2	13.0
2.00	1.91			6.0	14.5	9.1
4.12	4.02			6.0	10.8	8.0
6.12	6.01			6.0	6.8	6.0
8.50	8.45			6.0	5.2	9.0

General:
Processes used for surfacing CR-39^® lenses can be applied to the SunSensors lenses. Please note that SunSensors lenses have a refractive index of 1.555.

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 SunSensors 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.

Cribbing:
Cribbing during generating SunSensors lenses may increase breakage. Cribbing may create hairline fractures in the new edge of the lens which could cause this lens to break during post- generating processes. We recommend you evaluate your processes for this potential cause of breakage.

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 approximately 1/3mm to the temporal side of 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 -2mm down and 2.7mm in.

Removal/Re-marking the Temporary Reference Marks:
The Navigator Progressive Lens markings may be removed by wiping the surface with alcohol or standard lens mark removing solvents. To re-mark the Navigator Progressive Lens, locate the semi-visible "+" symbols engraved along the 0-180° axis line. Use a felt pen to mark a spot over the "+" symbols, and trace the progressive markings using the Kodak Progressive Lens verification mask or the Progressive Lens center/sizing chart. Use the fitting cross to accurately optimize optics during final fitting of Navigator Progressive Lenses.

Semi-Visible Markings
Navigator Progressive Lens markings have a "+" at the nasal and temporal sides along the 180° axis line. Located approximately 3mm below the nasal "+" is the Navigator icon and the letter "I". The add power is located approximately 3mm below the temporal "+". 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. While moving the lens slowly, look through the lens for the semi-visible marks located along the surface of the lens. The marks will become visible at a given angle of light and be most visible as the lens nears the edge of the light fixture.

Fining and Polishing:
Processing the SunSensors lens material is similar to the CR-39 lens material with two exceptions: The stock removal during the fining can be greater, and SunSensors lenses can be polished in 2-3 minutes. See the following tables for our test results.

ONE-STEP Fining Pads	Millimeter Take-off
Pad Brand & Type	20 sec	40 sec	60 sec	80 sec
PSI P-1000	0.25	0.47	0.69	0.87
DAC Fire (Fine red vinyl)	0.20	0.40	0.60	0.75
Salem 933	0.20	0.40	0.60	0.75

TWO-STEP Fining Pads (DAC) Brand
Pad Type	20 sec	40 sec	60 sec	80 sec
1st Fine: 600 GRIT	0.26	0.48	0.69	0.87
Salem 993	0.30	0.59	0.86	1.10
2nd Fine: 9 MICRON BLUE	0.08	0.12	0.15	0.17
Salem 1128	0.13	0.19	0.23	0.27

POLISHING TIME ( 2- 3 minutes)

Allow 0.1mm Take-Off

Abrasion Resistance Coatings:
The front surface of the SunSensors lenses includes the superior protection of RLXPlus non-tintable coating. The uncoated rear surface of the lens provides adequate durability for normal use. Therefore, a backside coating is not required unless an AR coating is to be used.

Impact Resistance:
As a component, lenses of this design have been shown by testing to be capable of being processed to meet applicable impact resistance requirements of FDA regulation 21 CFR 801.410 and ANSI Z80.1. Conformance to this standard is the responsibility of all subsequent processors. Impact resistant lenses are not unbreakable. Obviously damaged lenses should be replaced immediately.

CAUTION
Dispensing Note: At cooler temperatures, 53 degrees F (12 degrees C) and below, photochromic plastic lenses may become very dark on bright sunny days and may be too dark for driving any type of open-air vehicle. At colder temperatures, particular caution should be used when going from sunny to shady areas.

Drilling
SunSensors lenses can be successfully drilled and mounted into a three-piece rimless frame. However, we discourage the use of three-piece frames with other than polycarbonate plastic lenses as it may result in higher warranty returns. The pressure on a screw mount, when subjected to excessive bending force, is often sufficient to crack most plastic lenses. For the strongest drilled plastic lens, we recommend the following:
Use a bur-type bit (vs. a twist drill bit) and grind slowly through the material. Automated drilling machines should be set on the polycarbonate mode or the slowest feed rate. Chamfer the holes on the front and back of the lens with a cone-shaped tool. Use nylon Top Hat bushings in the holes for cushioning. Do not over-tighten the screws.

AR Coating:
Multi-layer AR coatings can be applied to SunSensors Lenses but a backside coating must also be applied if doing so. 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. Be sure that your AR coating is compatible with your backside coating. We recommend HT-1000 by Gerber-Coburn, UVNV or UVNVS by Ultra Optics. Confirm that sample lenses with your backside and AR coatings meet the FDA impact regulation before you begin selling AR coated SunSensors lenses. 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. Please call Technical Services at 800-759-0075 for additional information about coatings and impact resistance.

Tinting:
SunSensors lens material is tintable. It is important to use caution when tinting, as SunSensors lenses absorb tints much faster than most other plastic lens materials. If you decide to tint the lens, test a sample lens first. Note: Many tint neutralizer products will damage the lens. Call Technical Services at 800-759-0075 for additional tinting information.

Corning and SunSensors are registered trademarks of Corning Incorporated, Corning, New York
CR-39 is a registered trademark of PPG.
RLXPlus is a registered trademark and Navigator is a trademark of Signet Armorlite, Inc.

Navigator Progressive Lens in SunSensors
BASE CURVE SELECTION (MINUS)											BASE CURVE SELECTION (PLUS)
	Cylinder											Cylinder
Sphere Power	-0.50	-1.00	-1.50	-2.00	-2.50	-3.00	-3.50	-4.00	-4.50	-5.00	Sphere Power	-0.50	-1.00	-1.50	-2.00	-2.50	-3.00	-3.50	-4.00	-4.50	-5.00
-4.00											6.00
-4.25					4.50 Base						5.75
-4.50											5.50				7.75 Base
-4.75											5.25
-5.00											5.00
-5.25											4.75
-5.50											4.50
-5.75											4.25
-6.00											4.00
-6.25					2.00 Base						3.75
-6.50											3.50
-6.75											3.25
-7.00											3.00
-7.25											2.75
-7.50											2.50
-7.75											2.25
-8.00											2.00				5.75 Base
-8.25											1.75
-8.50											1.50
-8.75											1.25
-9.00											1.00
-9.25											0.75
-9.50											0.50
-9.75											0.25
-10.00											0.00
-10.25											-0.25
-10.50											-0.50
-10.75					0.50 Base						-0.75
-11.00											-1.00
-11.25											-1.25
-11.50											-1.50
-11.75											-1.75
-12.00											-2.00				4.50 Base
-12.25											-2.25
-12.50											-2.50
-12.75											-2.75
-13.00											-3.00
-13.25											-3.25
-13.50											-3.50
-13.75											-3.75
-14.00											-4.00

SunSensors Single Vision and Flat Tops
	Cylinder
Sphere Power	0.00	-0.25	-0.50	-0.75	-1.00	-1.25	-1.50	-1.75	-2.00	-2.25	-2.50	-2.75	-3.00	-3.25	-3.50	-3.75	-4.00	-4.25	-4.50	-4.75	-5.00
7.00
6.75
6.50			8.50 Base
6.25
6.00
5.75
5.50
5.25
5.00
4.75
4.50
4.25
4.00
3.75
3.50
3.25
3.00
2.75
2.50									6.12 Base
2.25
2.00
1.75
1.50
1.25
1.00
0.75
0.50
0.25
0.00
-0.25
-0.50
-0.75
-1.00
-1.25
-1.50
-1.75
-2.00									4.12 Base
-2.25
-2.50
-2.75
-3.00
-3.25
-3.50
-3.75
-4.00
-4.25
-4.50
-4.75
-5.00
-5.25
-5.50
-5.75
-6.00
-6.25
-6.50									2.00 Base
-6.75
-7.00
-7.25
-7.50
-7.75
-8.00
-8.25
-8.50
-8.75
-9.00
-9.25
-9.50
-9.75
-10.00
-10.25									0.50 Base
-10.50
-10.75
-11.00
-11.25
-11.50
-11.75
-12.00
-12.25
-12.50
-12.75
-13.00