title: Instrument for measuring relative brightness perception.
abstract: Neuro-ophthalmic disorders may cause a subjective difference in the brightness perceived by each eye. We developed a unique clinical device to measure this difference. The device consists of a disk equipped with graded neutral-density filters that fits into a View-Master stereo viewer (View-Master International Group, Inc., Portland, Oregon). This device provides simultaneous viewing of a stimulus target for each eye, and is administered in a random, forced-choice format that allows assessment of patient reliability. We administered this test to 37 control subjects and 84 patients with a variety of disorders. Thirty-six of the 37 control subjects (97%) and 51 of the 84 patients (61%) had no measured relative brightness deficit and no errors. Of the 34 subjects who had abnormal results, 21 (62%) isolated a relative brightness deficit within 0.2-log unit steps without error, and 28 (82%) did so within 0.4-log unit steps. This device proved to be a simple, reliable instrument for measuring relative brightness perception.
authors.affiliation: Department of Ophthalmology, Bowman Gray School of Medicine, Wake Forest University Eye Center, Winston-Salem, North Carolina 27157.
authors.forename: T J
authors.initials: TJ
authors.lastname: Martin
authors.forename: G D
authors.initials: GD
authors.lastname: Robison
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D006801:Humans; D008027:Light; D008875:Middle Aged; D009885:Ophthalmology / Q000295:instrumentation*; D015203:Reproducibility of Results; D012684:Sensory Thresholds; D014786:Vision Disorders / Q000175:diagnosis*; D014792:Visual Acuity; D014796:Visual Perception