Base Curves: 1.25, 3.25, 5.50, 7.50

Power Range: -8.50 to +5.00

Add Powers: 1.00 to 3.00 in 0.25 Diopter Steps

General:
Processes used for surfacing CR-39^® lenses should be applied to Navigator Short Lenses.

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 Navigator Short Progressive 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. 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 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 2.2mm in.

Removal/Re-marking the Temporary Reference Marks:
The Navigator Short Progressive Lens markings may be removed by wiping the surface with alcohol or standard lens mark removing solvents. To re-mark the Navigator Short 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 Navigator Short Progressive Lens verification mask or the Progressive Lens center/sizing chart. Use the fitting cross to accurately optimize optics during final fitting of Navigator Short Progressive Lens.

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. Lenses with visible damage should be replaced immediately.

AR Coating:
Because lens impact resistance is reduced by AR coatings, we recommend a 2.0mm 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.

The simplest and most accurate way to ensure that an adequate distance & near area will be enclosed within the frame is to use Signet Armorlite's center/sizing chart for Navigator Short Lenses. Mark each fit point on the demonstration lenses in the frame and lay it over the center/sizing chart to verify 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.