To re-mark the lens, first locate the semi-visible markings, specifically the "+" symbols engraved along the 180† axis line (see above procedure for locating the semi-visible marks). Once you have located the semi-visible marks, use a felt pen to mark a spot over the "+" symbols and use the Kodak Concise verification chart for the final re-marking.

AR Coating:
Multi-layer AR coatings can be applied to Kodak Concise Lenses. 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. 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.

Cribbing:
Cribbing too aggressively 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.

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 2-4 minutes. See the following tables for our test results at 19PSI.

Tinting:
SunSensors lens material is tintable. We recommend against tinting since it reduces the reaction of the photochromic dyes and may result in too dark of a lens. Additionally, 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 for recommended tinting procedures or for additional information at 800-759-0075.

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:

Fitting and Frame selection:
Our minimum segment height guideline is 17mm, based on the 12mm corridor length. The measurement includes 2mm above the reference dot where the fitting cross is marked, as well as 3mm of clear area below the full addition location. Minimum segment height values are completely Rx and frame dependent. The frame shape and patientís monocular PDs will affect this minimum segment height, which is measured from the lowest point of the frame and not the lowest point of the frame where the reading area falls. Illustration 1.0 shows that the near zone may not fall inside the frame for certain frame and monocular PD requirements.

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 Kodak Concise 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.

Illustration 1.0