. A Reference handbook of the medical sciences : embracing the entire range of scientific and practical medicine and allied science. cylinder itselfaround its own axis, by their combinations, may placethe ivory ball in all meridians of a sphere concentricwith the eye. Badals perimeter likewise consists of atube with lateral slit, and a movable portion for measur-ing the inclination of the meridians. To this is added aquadrant of a circle, with a radius of 15 centimetres,placed on end at one extremity of the tube. The otherend is bell-shaped and is placed against the eyelids. Thequadrant is gra
. A Reference handbook of the medical sciences : embracing the entire range of scientific and practical medicine and allied science. cylinder itselfaround its own axis, by their combinations, may placethe ivory ball in all meridians of a sphere concentricwith the eye. Badals perimeter likewise consists of atube with lateral slit, and a movable portion for measur-ing the inclination of the meridians. To this is added aquadrant of a circle, with a radius of 15 centimetres,placed on end at one extremity of the tube. The otherend is bell-shaped and is placed against the eyelids. Thequadrant is graduated in spaces of 5° up to 90°, and onthe quadrant runs a cube the four sides of which arepainted a different color—white, red, green, and violet—which may be presented in turn toward the eye of thepatient. Beyond the disk is a tube by which the instru-ment is to be held. During the examination the patientholds the instrument by the handle, while the bell-shaped end is placed against the eye to be examined, theother eye being kept closed. The examiner stands be-hind the patient and moves the ivory cube until it is seen. Fig. -1597.—Meyers Perimeter. by the patient. The figures inscribed upon the quadrantand on the movable disk give the meridian in whichthe examination has been made, and the limit of the vis-ual field in the corresponding meridian. Meyers perimeter combines the advantages of the field-measurement and of perimetry. The instrument con- 661 REFERENCE HANDBOOK OF THE MEDICAL SCIENCES. sists of a quadrant which, rotating round its summit,describes a hemisphere, at the centre of which the pa-tients eye is to be placed, and should be fixed on themark at the apex of the arc, the other eye being arc of the perimeter being placed in a given plane,the observer moves the carriage (C) slowly from the pe-
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectmedicine, bookyear188
