Products

Introducing Precal

OPTIMISED THICKNESS FOR ALL LENSES

Precal is a lens calculation process which predetermines the thickness of a glazed lens, based on lens and frame shape, prescription and centration. Precal calculates the minimum centre thickness to which a lens can be surfaced to provide the thickness appropriate to the lens/mount combination. The Precal calculation will only be applied when specified by the customer.

PARAMETERS REQUIRED FOR PRECAL

PROVIDE FULL PRESCRIPTION

  • Lens Type
  • Prescription RE & LE.
  • Coatings/Tints
  • Frame Type

Sample 1

RX
SPH
CYL
AXIS
PRIMS
ADD
O.D
-1.50
-0.50
010
+2.25
O.S
-1.25
+2.25

Sample2

RX
SPH
CYL
X
AXIS
PRIMS
ADD
O.D
-150
-50
010
+225
O.S
-120
+225

Sample 3

RX
SPH
CYL
AXIS
PRIMS
DISTANCE
O.D
-1.50
-0.50
010
O.S
-1.20
NEAR
O.D
+0.75
O.S
+1.00
-0.50
10

FRAME DETAILS

  • Frame A measurement.
  • Frame B measurement.
  • DBL the frame D measurement.

PUPILLARY DISTANCE & HEIGHT

  • Monocular P.D measurement.
  • Frame height for both RE and LE.

FRAME SHAPE OUTLINE

Provide the outline of the selected frame.

OR

Choose from one of the standard 8 precal shapes which is closest to the selected frame shape.