rical and cylindrical lenses therehas come into use in recent years, although known of long before, a type oflens having a toric surface. These toric lenses, as they are called, have comeinto favor where the advantage of the periscopic principle in connection withcylindric effect is sought. From… … Fig. 17 Perspective View of Toric Lens and Torus lenses offers many difficulties. Fig. 17 presents a perspective view of a torus.The plano-convex lens shown may be considered cut out of this torus andhaving the meridians a c b and d c e. In Fig. 18 are shown sectional views through the vertical…
Lenses · Eyeglasses
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