Title:
SUBJECTIVE REFRACTIVITY EXAMINATION APPARATUS
Document Type and Number:
Japanese Patent JP2740936
Kind Code:
B2
Abstract:
PURPOSE: To easily perform the examination of astigmatism by simple constitution by separating the luminous flux of a target into two luminous fluxes and providing cross cylinder testing lenses equal in optical characteristics but arranged so that the axes of them are different by 90° to the respective light paths of the separated luminous fluxes and displaying an image separating direction on a display means.
CONSTITUTION: In this subjective examination of refractivity wherein a examinee responds while looks optotypes through various lenses arranged in front of an eye 2 to be examined, lens discs 4A, 5, 6, 12, 13 to which a plurality of auxiliary lenses 7, strong spherical lenses 8, weak spherical lenses 9, positive astigmatic lenses 14 and negative astigmatic lenses 15 are arranged are arranged. Further, a disk 4B having cross cylinder testing lenses formed by bonding two cross cylinder lenses of which the axes are mutually different by 90° to a left and right symmetric prism thick at the center part thereof and thin at the peripheral part thereof arranged thereto is provided. By this constitution, light is deflected from optotypes by the prism and the optotypes are separated into two directions of a glance to be observed.
Inventors:
Akihiro Hayashi
Application Number:
JP33879793A
Publication Date:
April 15, 1998
Filing Date:
December 01, 1993
Export Citation:
Assignee:
NIDEK CORPORATION
International Classes:
A61B3/036; A61B3/028; (IPC1-7): A61B3/028
Domestic Patent References:
| JP60193436A |
Other References:
「眼科器械の使い方」（Ｓ５５−２−１）医学書院Ｐ４〜１１
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