ONE OF the most difficult problems in perimetry has been the elimination of distraction in the examination. Test-object carriers; the examiner's hand and clothing; light reflected from marking pins, chalk, and perimeter arcs, and extraneous room light, all distract the patient's attention from both the fixation target and the test object in the peripheral field, thus adding to the difficulty of performing the examination and detracting from its accuracy.
The examination of the visual field by perimetry is a subjective test. It is the patient's interpretation of what he sees that determines the accuracy and validity of the test, and it is the visualization of the test object in relation to the fixation target that determines the extent of the visual field as interpreted by the individual patient. Any method which simplifies the test for the patient by eliminating distracting stimuli from within the field of vision so that only
HARRINGTON DO. PERIMETRY WITH ULTRAVIOLET (BLACK) RADIATION AND LUMINESCENT TEST OBJECTSA Preliminary Report. AMA Arch Ophthalmol. 1953;49(6):637-642. doi:10.1001/archopht.1953.00920020650004