GB597583A - Optical viewing device - Google Patents

Abstract

597,583. Optical viewing devices. DYKES, W. U. (Research Corporation). April 9, 1945, No. 8712. [Class 97 (i)] A device for viewing juxtaposed areas having different light characteristics with equal effectiveness, such as, a strong light source and the area surrounding it, comprises at least one pair of oblong elements adapted to transmit, absorb, modify or obturate light, one element of each pair being positioned in the path of vision of each eye and one element being disposed substantially horizontally and at right angles to the other element. The oblong elements may be integral with or detachably mounted upon light transmitting means, such as a lens or window, which has different light characteristics from said elements. Thus, the light transmitting means may pass light at a greater intensity than the oblong elements or may absorb light of a colour which is transmitted by said elements. As shown in Fig. 1, an ordinary spectacle frame holds lenses 13 integral with which or detachably mounted thereon are oblong patches 14a, 14b with their major axis at right angles. When the patches have greater density than the lens material on looking through the spectacles a dark cross is seen having a darker square at the crossing of its arms, this square having the axis of binocular fusion of the two patches in which a strong light source can be centred and the glare reduced so that no strain is placed on the eye when increasing the area around the light source. Alternatively, a light cross having a ligher square at its centre may be provided by using patches of less density then the lens material. The device may also be used, e.g. in goggles, welder's screens and visors.