US PATENT SUBCLASS 351 / 241
.~.~.~ Astigmatism type


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

200  DF  EYE EXAMINING OR TESTING INSTRUMENT {7}
222  DF  .~ Subjective type {7}
239  DF  .~.~ Including test chart or target {5}
241.~.~.~ Astigmatism type


DEFINITION

Classification: 351/241

Astigmatism type:

(under subclass 239) Subject matter comprising eye test charts having for example changeable color lines or colored contour bands, to determine the axis and amount of astigmatism and the required cylindrical lens axis.

SEE OR SEARCH CLASS

40, Card, Picture, or Sign Exhibiting,

446+, for changeable exhibitors, and subclasses 541+ for illuminated signs.