US PATENT SUBCLASS 351 / 170
.~.~.~ With prismatic segment


Current as of: June, 1999
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351 /   HD   OPTICS: EYE EXAMINING, VISION TESTING AND CORRECTING

41  DF  SPECTACLES AND EYEGLASSES {29}
159  DF  .~ Ophtahalmic lenses or blanks {10}
168  DF  .~.~ Multifocal {4}
170.~.~.~ With prismatic segment


DEFINITION

Classification: 351/170

(under subclass 168) Subject matter wherein one of the multifocal lens elements has a specific prismatic correction whose prism base is located relative to the optical center of the distance and/or intermediate vision lens sections to give the desired correction.

(1) Note. The lens section with prismatic correction may be in the form of a segment fused into a lens countersink or the prismatic correction may be formed by grinding a desired area of a multifocal lens made of one piece of material.

SEE OR SEARCH THIS CLASS, SUBCLASS:

175, for prismatic-type ophthalmic lenses generally.