Importance

Loading Importance Indicators...

Abstract

The invention refers to an arrangement for the carrying out of eye examinations by means of an optotype mask which is illuminated from behind. It consists therein that the optotype mask is arranged in front of the picture screen of a video tube which serves as source of illumination and that means are provided by which the picture-screen presentation can be controlled with respect to brightness, color, contrast, partial or full surface illumination and blending-in of additional static or moving structures in order to carry out different eye tests. In this connection the optotype masks may be exchangeable or be moved over the picture-screen surface by a mechanical drive between different eye tests. Furthermore, the optotype mask may consist of flexible material which may be moved past the surface of the picture screen between different eye tests. Furthermore, means are provided by which both the exchange of the optotype mask and the control of the picture-screen display can be programmed for automating the eye tests. Instead of the video tube and optotype mask there can also be provided a double arrangement consisting of the optotype mask and a flat display which--self-illuminating or reflective--serves as source of illumination or a triple arrangement consisting of the optotype mask and a flat display which serves by transmission as light-valve plane for a static source of illumination arranged behind it.

Loading the Abstract Image...

First Claim