Ophthalmometer having afocal lens system

Claim 1

IN A OPHTHALMOMETER, THE COMBINATION OF TWO MIRES LYING IN A PLANE PASSING THROUGH THE LOCATION OF THE LINE OF VISION FOR THE PATIENT''S EYE, SYMMETRICALLY OF SAID LINE AND TO THE FRONT OF THE LOCATION OF THE PATIENT''S EYE, AN AFOCAL OPTIC SYSTEM LYING ALONG THE LOCATION OF SAID LINE OF VISION TO THE FRONT OF THE LOCATION OF THE PATIENT''S EYE AND AN IMAGE-DOUBLING SYSTEM EXTENDING ON THE SIDE OF THE AFOCAL SYSTEM OPPOSED TO SAID LOCATION OF THE PATIENT''S EYE AND INCLUDING A FIRST BEAM-SPLITTING SURFACE AND TWO SERIES OF REFLECTING SURFACES ADAPTED TO ACT ON EACH FRACTION OF THE SPLIT BEAM PASSING OUT OF THE FIRST SURFACE, TWO PARALLEL-SIDED TRANSPARENT PLATES INSERTED EACH IN THE PATH OF THE BEAM FRACTION PASSING THROUGH THE CORRESPONDING SERIES OF REFLECTING SURFACES, AN EYEPIECE LOCATED DIRECTLY BEYOND THE IMAGE-DOUBLING SYSTEM ADAPTED TO COLLECT AT LEAST PART OF EACH FRACTION OF THE SPLIT BEAM FOR SIMULTANEOUSLY OBSERVING THE IMAGES OF THE MIRES REFLECTED BY THE PATIENT''S CORNEA AND PASSING THROUGH THE AFOCAL SYSTEM AND THROGH THE CORRESPONDING SERIES OF REFLECTING SURFACES AND ASSOCIATED PARALLEL-SIDED PLATES, MEANS FOR ADJUSTING THE RELATIVE ANGULAR SETTING OF THE TWO PARALLEL-SIDES PLATES.