1. Availability
Establish that the prescription is within range in the diameter required.
2. Provide full prescription
■ Lens type
■ Prescription
■ Tints and/ or coatings
■ Frame type or edge thickness. Quote the minimum distance between lenses (measured at the nasal points, NOT HCL)
3. Shape outline
Draw around former or glazed lens with point of pen inclined inwards to
ensure outline is true size and shape. Indicate the A, B measurements of
the lens shape on the order. This eliminates any errors caused by
drawing or faxes being stretched.
4. Centration
Quote right and left monocular PDs.
Quote right and left fitting heights* |
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5. Frame details
State frame type or quote the lens edge thickness required at the
thinnest point, no less than 1mm. If no edge thickness is quoted for a
rimless frame we will automatically aim for 1.5mm at thinnest edge
(depending on frame) ensuring 2mm or 2.5mm at drill holes depending on
lens material. Essilor give a minimum edge thickness of 2mm for Nylor
frames.
You may also order Precal by telephone by quoting the lens type, prescription and coatings etc. accompanied by:
■ A standard shape number
■ The A box measurement
■ The B box measurement
■ The boxed minimum distance between lenses
■ The thinnest glazed edge requirement or Frame type e.g. metal, plastic, supra, rimless
Tip - When it is difficult to clearly define the shape by number, SHAPE
No.7, (a rectangular shape with rounded corners) or SHAPE No.5, (an oval
shape) have been found to give consistently good results.
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