OPTICAL VIEWING APPARATUS FOR A PATIENT HAVING MALADY OF VISION

摘要

1454273 Treating eyes D S REHM 31 Oct 1973 [6 Nov 1972 18 Oct 1973] 50697/73 Heading A5R [Also in Division G2] A head-mounted viewing apparatus for use in treating myopia, &c comprises a beam-splitter 72 having a semi-reflecting surface which divides an incoming beam of light and directs the two beams by way of reflectors 74, 78, 80 to two viewing apertures 76, 82, and is further provided with means for interchangeably mounting a lens or lenses in the incoming light path and/or in the viewing apertures 76, 82; these lenses are selected from a set of lenses of decreasing optical power within a prescribed range which may include zero. As shown, the apparatus housing is formed integrally with a spectacle frame. In an alternative arrangement the apparatus is supported on a spectacle frame by means of hooks, the frame itself forming the lens mounting means. The relative positions of the reflectors 74, 78, 80 are adjustable to cope with variations in interpupillary distances. The reflecting surfaces and beam splitters may be provided by prisms. The apparatus is used while reading, to provide the illusion of an image at infinity, the power of the lenses being changed in the positive direction by increments of 0.5 dioptres after the eyes have adjusted to the existing power of the apparatus.