Wide-angle ophthalmoscope

Claim 1

In a hand-held ophthalmoscope, a housing having a hollow interior, an optical illuminating system carried by said housing in the interior thereof and including a light source and a lightdeflecting means for directing light along an optical axis of said illuminating system from said light source toward an eye which is to be viewed, said optical illuminating system including a wide angle objective situated along said optical axis between said light source and said light-deflecting means, an observation system also carried by said housing and including a rotary lens wheel carrying a plurality of lenses for situating a selected lens along an observation light path of the observation system at that part thereof through which the operator observes the eye, said rotary lens wheel being supported for rotary movement by said housing and being made of a transparent material provided with an inner surface directed toward and communicating with the interior of the housing at an interior portion thereof which is axially displaced along said optical axis from said light source between the latter and said light-deflecting means and said rotary lens wheel having an outer surface directed outwardly toward the operator and carrying indicia for respectively indicating which of the lenses of the lens wheel is in an operative position at the observation path, and light-conducting means situated entirely in the interior of said housing and being spaced in its entirety radially beyond said optical axis and extending parallel to said optical axis from a location situated beside said light source to a location communicating with said interior portion of said housing with which said inner surface of said rotary lens wheel communicates for receiving light radiating radially from said light source and for conducting the received light along a path spaced radially beyond and extending parallel to said optical axis into said interior portion of said housing to illuminate said inner surface of said transparent lens wheel for directing through the latter light which illuminates the indicia even in the dark, so that the operator knows which of the lenses has been located at the observation path.