Yeda Research and Develpment & Co. Ltd

Med Optics Corporation

Samuel Ron

Jehoshua Wolowelsky

Itshak Levy

Abraham Sahar

A method and system for presenting two successive images on a video display unit as a dichoptic stimulus of substantially equal intensity, wherein a first image is displayed at a predetermined intensity so as to be seen by a first eye of an observer only, an optical shutter being used to prevent the displayed image from reaching the second eye of the observer. The first image is then extinguished and the state of the optical shutter reversed so that the first eye can no longer see the video display unit whilst a second image is presented to the second eye. In order to prevent the second eye from seeing an after image of the first image, a neutral density filter or polarizer is disposed within the light path and the second image is illuminated at a correspondingly higher intensity so as to compensate for the attenuation factor of the neutral density filter or polarizer. Such a method may be employed to measure the dark vergence of the observer which has been found to be a major factor in determining fatigue of computer operators, in order that corrective action may be taken so that the angle subtended by an image on the computer screen at the eyes of the observer may be adjusted to the angle of dark vergence. Such corrective action may be provided by individually tailored prismatic spectacles.

Ophthalmological instrument for producing dichoptic stimuli on a visual

An actuator device comprising a housing in which there is arranged a permanent magnet extending at 90.degree. from an axially supported member, said member being attached to a driving pawl via a springy leaf, the movement of said magnet being limited by two stop members attached to the bottom plate of the housing, a ratchet wheel with a plurality of teeth pointing downwards and adapted to be engaged by said pawl, another pawl attached to a springy member rigidly attached to said housing, the pawl being adapted to stop a reverse movement of the ratchet wheel, the arrangement being such that application of a magnetic field of adequate strength from a certain distance results in the movement of the magnet and the pawl attached thereto within the range defined by the stop members, each such movement resulting in the stepwise advance of the ratchet wheel by one tooth.

Growing community of inventors

Ramat Hasharon, Israel

Samuel Ron