slab-off

slab-off

(slab-of'),
A process by which prism base-up is produced in the reading field of a spectacle lens through bicentric grinding.
References in periodicals archive ?
Prism-free optics or peri-ballast is used to incorporate the stabilising prism only in the peripheral areas of the lens, for example UltraVision LiteWave (Figure 2) and the slab-off prisms give equal thickness at both the base and 3 and 9 o'clock positions.
The "revolutionary" back toric design features double vertical asymmetric slab-off and horizontal right and left ballast for axis stabilisation.