GB522148A - Improvements in apparatus for examining eyes for refractive errors - Google Patents

Abstract

522,148. Sight-testing apparatus. KAESZ, S. Dec. 1, 1938, No. 35012. [Class 97 (i)] Sight-testing apparatus comprises adjustable optical means for transmitting an image reflected from the eye to a kinematograph film, together with means for simultaneously photographing on the film a record of the adjustment of the optical means. Fig. 2 shows an ophthalmoscope comprising a disc 1 carrying a series of lenses 2 and driven in a step - by - step manner through a maltese-cross mechanism by the motor 3 which drives the film 5 of a kinematograph camera. Light from a source 18 is reflected from an adjustable mirror 21 to the eye and thence back through the lens 2 which is in operative position, the image being recorded on the film 5. Simultaneously an identification mark on a window 14 illuminated by a lamp 15 is recorded on the film; the identification mark may alternatively be on the lens 2. Fig. 5 shows a retinoscope in which the concave mirror 22 is supported on a cylinder 26 which is turned about a vertical axis by means of a disc 23 coupled to it by a link 25 and rotated by the motor 3 of the kinematograph camera. The cylinder 26 has a transparent wall carrying an illuminated scale 28; an image of the scale and of a fixed pointer 29 being thrown on to the film by means including a biprism 30, together with the image reflected from the eye.