Freeform Software

Crossbows can provide freeform software for the production of finished progressive lenses from semi-finished spheres where the progressive surface is machined on the concave side and incorporates the patient's prescription. File outputs can be generated for a range of freeform equipment including machinery from Schneider, Optotech, Satis-LOH, Gerber Coburn, DAC, Comes and VCA standard output. The software has the ability to be integrated with VCA compliant Lab Management Systems.

Different designs are available to suit a wide variety of frame sizes and patients' needs. The corridor lengths are measured from fit point to the centre of the reading reference circle i.e. to 100% of full add power, unlike some of our competitors.

Technical suppport is available at no extra cost.

Benefits of Back Surface Progressives:

• Premium products at reduced costs - only requires a stock of semi-finished spheres in each material. Not restricted to purchasing semi-finished spheres from Crossbows.
• Progressive on the back surface to maximize fields of view in the corridor and reading areas
• Patients distance correction is incorporated into the progressive design to improve accuracy of prescription

Crossbows Freeform Designs:

Crossbows can offer four different progressive designs.

• Custom 14
• Custom 18
• Custom Office
• Custom Junior

You can choose to use these brand names or if you wish you may market the lenses under your own name.

Software Features

The Crossbows freeform software is simple to use and can be run in two different modes. It can act as a standalone program which can provide a simple interface for entering freeform prescriptions and will produce output files for the machines mentioned above. It can also be run as a server program and this can be integrated with a suitable Laboratory Management System to function automatically. The software is compliant with latest VCA freeform standards.

Optimisation of centre and edge thicknesses can be carried out in a number of ways depending on the information available:

1. No Frame Information - where the prescription is calculated for a circular or elliptical blank of specified dimensions.
2. Frame Box Dimensions - where the user enters the frame box dimensions, fitting dimensions and blank dimensions. The centre and edge thicknesses are then optimised using this data.
3. Frame Digitized Data - where the frame tracing information is available in a file. In this case the user only has to enter the file name and fitting information. The centre thickness, edge thickness at the frame shape, edge thickness at the crib shape and the crib dimensions are then optimised using this data.

Examples of the data input screens are shown below. Click on the pictures for a larger image.