TIPS NO	245
Revision	B
Date:	Sept 2007

 

 

 

 

 

Signet SRC Standard Resin

Single Vision 70 & 75, Flat-top 28/70 & 35/70 Bifocals,

and 7x28/70 Trifocal Lens Product Specifications.

 

Purpose: The following information provides basic processing information for the Signet SRC 70mm & 75mm Single Vision, Flat-top 28/70 & 35/70 Bifocals, and 7x28 Trifocal lenses. (Based on a 1.530 Tooling index.)

Revision: The 75mm Single Vision, Bifocal 28/70, Bifocal 35/70, and Trifocal 7x28 base curves and adds have been extended.

 

Characteristics	Signet SRC Lens
Refractive Index	1.499
Dispersion Value (Abbe)	58.0
Density	1.32
Visible Light	92%
Rear Surface Coating	Optional
Scratch Resistance	In-mold RLXPlus®
Heat Distortion	165ºF, 74ºC
UV Transmission Cutoff	355 nm
Chemical Resistance	Excellent
Machinability	Excellent
Coating	Scratch Resistant Coating

 

Blank Size:          70mm and 75mm diameter

Base Curves:      0.50¹, 2.00, 4.25, 5.25², 6.25, 7.25³, 8.25, 9.25³, 10.25

¹ Available in 70mm SV, 75mm SV, FT28/70 & FT35/70
² Available in 70mm SV and FT28/70
³ Available only in 70mm SV

Power Range:   
70mm SV: -9.00 to +8.00
75mm SV, FT28/70 & FT35/70, TRI 7X28/70: -7.25 TO +7.00

Add Powers:      
FT28/70: 0.75 to 4.00 in 0.25 Diopter steps,
               4.00 to 6.00 in 0.50 Diopter steps
FT35/70: 1.00 to 4.00 in 0.25 Diopter steps
7x28/70: 1.50 to 4.00 in 0.25 Diopter steps,
               4.00 to 6.00 in 0.50 Diopter steps

Flat-Top Inset:Bifocal: 5mm in, 5mm down
Trifocal: 5mm in, 1mm down

70mm Single Vision Lenses

Nominal Curve	True Curve	Radius mm	SAG at 50mm	Nominal Concave	Edge Thickness	Center Thickness
0.50	0.42	1261.905	0.25	6.75	17.0	9.4
2.00	2.03	261.084	1.20	6.75	14.5	8.8
4.25	4.29	123.543	2.56	6.75	11.0	8.0
5.25	5.21	101.727	3.12	6.75	11.0	9.1
6.25	6.22	85.209	3.75	6.75	11.0	10.3
7.25	7.21	73.509	4.38	6.75	7.0	7.0
8.25	8.18	64.792	5.02	6.75	7.5	10.3
9.25	9.21	57.546	5.71	6.75	6.8	10.0
10.25	10.29	51.506	6.47	6.75	7.5	13.7

 

 

 

 

 

 

 

 

 

75mm Single Vision Lenses

Nominal Curve	True Curve	Radius mm	SAG at 50mm	Nominal Concave	Edge Thickness	Center Thickness
0.50	0.4	1325.0	0.23	6.75	16.0	7.5
2.00	2.03	261.084	1.20	6.75	16.0	10.0
4.25	4.29	123.543	2.56	6.75	12.0	9.1
6.25	6.22	85.209	3.75	6.75	9.0	8.6
8.25	8.18	64.792	5.02	6.75	11.5	14.0
10.25	10.31	51.406	6.48	6.75	10.9	17.5

 

 

Flat-Top 28/70

Nominal Curve	True Curve	Radius mm	SAG at 50mm	Nominal Concave	Edge Thickness	Center Thickness
0.50	0.48	1104.167	0.28	6.75	16.5	9.4
2.00	2.03	261.084	1.20	6.75	14.5	8.8
4.25	4.29	123.543	2.56	6.75	11.0	8.0
5.25	5.21	101.727	3.12	6.75	11.0	9.1
6.25	6.22	85.209	3.75	6.75	11.0	10.3
8.25	8.2	64.634	5.03	6.75	7.5	10.3
10.25	10.59	50.047	6.69	6.75	8.0	13.7

 

 

 

 

 

 

 

 

 

 

 

Flat-Top 35/70

Nominal Curve	True Curve	Radius mm	SAG at 50mm	Nominal Concave	Edge Thickness	Center Thickness
0.50	0.48	1104.167	0.28	6.75	16.5	9.4
2.00	2.01	263.682	1.19	6.75	14.5	8.8
4.25	4.14	128.019	2.46	6.75	11.0	8.0
6.25	6.26	84.665	3.78	6.75	11.0	10.3
8.25	8.41	63.020	5.17	6.75	7.5	10.3
10.25	10.59	50.047	6.69	6.75	8.0	13.7

 

 

TRIFOCAL 7X28

Nominal Curve	True Curve	Radius mm	SAG at 50mm	Nominal Concave	Edge Thickness	Center Thickness
2.00	2.01	263.682	1.19	6.75	14.5	8.8
4.25	4.14	128.019	2.46	6.75	11.0	8.0
6.25	6.26	84.665	3.78	6.75	11.0	10.3
8.25	8.41	63.02	5.17	6.75	7.5	10.3
10.25	10.59	50.047	6.69	6.75	8.0	13.7

 

General: Standard pads and polish materials used for surfacing CR-39^® lenses can be applied to the SIGNET SRC 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 Signet Lens design data. If your software does not include this data, 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.

 

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.

 

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 of FDA Regulations 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.

CR-39 is a registered trademark of PPG

RLXPlus is a registered trademark of Signet Armorlite

 

 

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.