. A treatise on diseases of the eye . )hysiological blind spot thecentre of the field. Perimeters have been constructed in which the pivot around whichthe arc of the perimeter revolves is perforated. The patient is directedto look through the small hole and fix an object in a distant part of theroom. This device is resorted to in order to ])revent the contractionof the pupil which accompanies accommodation for an object at 30 Monocular field of vision, horizontal meridian projected on an arc 0 L and on a tangent A , n, lateral limit; M, m, median limit; F, f, point of fixation; A^, 71,
. A treatise on diseases of the eye . )hysiological blind spot thecentre of the field. Perimeters have been constructed in which the pivot around whichthe arc of the perimeter revolves is perforated. The patient is directedto look through the small hole and fix an object in a distant part of theroom. This device is resorted to in order to ])revent the contractionof the pupil which accompanies accommodation for an object at 30 Monocular field of vision, horizontal meridian projected on an arc 0 L and on a tangent A , n, lateral limit; M, m, median limit; F, f, point of fixation; A^, 71, physiological blindspot. Examination.—The patient is placed in position with his back to thelight. The eye not under examination must be covered. The eye tobe examined is adjusted properly and the patient is requested to fixthe centre of the pivot of the perimeter arc which should bear a wiiiteobject 5 mm. in diameter. The test object, which may be a whiteball, 1 cm. in diameter, mounted on a small l)lack rod, or a white ])atcli1 cm. square mounted on a small black disk, should be approachedfrom the end of the arc and the point where the patient is first a[)le to seethe test object or to detect the color of the test object when the colorfields are being taken, should be noted. In making the examinafion,the patients eye must be carefully watched to detect any movement,as a change in the point of fixation will give inaccu
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecteyediseases, bookyear
