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Show Specfoces Seven-in-One Correction SOUTHBRIDGE, MASS. The correction of spectacles by grinding grind-ing the lens to take care of seven specific defaults has been reported re-ported here. The American Optical company, com-pany, which did the job, believes there has never been a similar instance and challenges the world to top Its achievement. The glasses were for a man whose eyes needed seven different differ-ent corrections and he wanted all the corrections in one pair. Here's what had to be corrected: First is nearsightedness. Second is need of a special glass for seeing intermediate distances. Third is a defect in his far-seeing. far-seeing. These three were met by trifocals. tri-focals. These took care of nearsightedness near-sightedness and of medium distance. dis-tance. A special curve had to be ground into the farsighted part of the lenses to get his distance-seeing distance-seeing right. Fourth, a curve ground to correct cor-rect double vision. This was done in the close-up-seeing part of the lenses. Fifth, one lens is wedge shaped, its top edge thicker than the bottom, because one eye cocks up higher than the other. Sixth, a special curve over everything to correct aniseikonia, which is seeing images of different differ-ent sizes with one eye as compared com-pared with the other. To do this, separate lenses were made, then fused on top of the trifocals. Seventh, ultraviolet light hurt his eyes, and the lenses were made of a glass which absorbs these rays. Five pieces of ophthalmic glass were used Instead of the usual one piece. |