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168 Ophthalmic Lenses

important factor, which is usually overlooked, is the ‘A’-measurement of
the frame, i.e., it must minimize the distance between the position of the
fitting cross and the temporal end of the frame.

Fig. 11.49: Sufficient height between the pupil and the lower rim of the frame

Once the lenses are properly marked and verified on the wearer’s face,
the layout card can be used to ensure the confirmation of above factors.

DISPENSING PROGRESSIVE ADDITION LENSES
Progressive lenses should be centered with respect to the eye so that the
vision zone can be used ideally at all distance. The fitting of progressive
lenses should be carried out with normal, relaxed head and body position
and with the eyes looking horizontally straight ahead. The fitting can be
done using manual measurement. But before that it is important that you
fit the selected frame on the wearers face and then take the measurement.
The following adjustment needs to be confirmed:
Frame Front Adjustment

Adjust the angle of the temples so that the frame sits squarely on the face.

Fig. 11.50: Front of the frame not in alignment