Essilor Pro-B 300, User Manual

Page: 66 / 140

The lens is centered and ready to be blocked.
To block the lens, refer to the section Centering a lens > Blocking a lens
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p.67)
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7. C
ENTERING A LENS FOR A HIGH
-
BASE FRAME
At the end of a tracing, if a frame is considered to be high based, the indicator is displayed in the
information bar.
3D compensation
The PD and pupillary height measurements as well as the lens centering are done in two dimensions. Yet,
the frame is treated in three dimensions:
3D compensation takes into account all frame characteristics (x, y, z, curve, pantoscopic tilt, etc.) to ensure
that the center of the wearer's pupil is at the optical center of the lens. For an optimal job, the on-screen
positioning of the centering indicators always takes account of 3D compensation.
Match between frame base and lens base
To do a job involving a high-base frame, use lenses whose base matches that of the frame (maximum
difference of 0.7 D).
To center a high-base lens, use the high-base tripod.
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Pro-B 300 > v1.0 - 03.19
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> III. C
ENTERING A LENS