Apparatus for Testing Errors of Refraction
Description:
Patent for an eye testing device that has a movable lens, a measuring device for correction, and two different cards with test type on them which are fed into the machine during testing for astigmatism and myopia, presbyopia, and hyperopia to determine the level of correction needed in glasses.
Date:
July 2, 1907
Creator:
Bahn, Gustavus Adolphus
Item Type:
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Partner:
UNT Libraries Government Documents Department