Page 177 - PowerPoint 演示文稿

Progressive Addition Lenses 167

Fig. 11.46: Ideal square shape of frame for progressive addition lens

Fig. 11.47: Ideal panto shape of frame for progressive addition lens

Fig. 11.48: Aviator shape cuts away the reading area in the nasal side
does not reduce the size of the reading area by being too “cut away” in the
nasal area of the frame. For example, an aviator shape frame coupled with
narrow pupillary distance may present such a difficulty.

Size/depth of the Frame
The frame must have sufficient depth to accommodate the entire zones of
the progressive lens from the top of the distance power circle to the bottom
of the near power circle within its aperture, i.e., the ‘B’ measurement should
be adequate to include full distance and near optical zones. Another