Brightness-sense and optic nerve disease
A. A. Sadun and S. Lessell
We describe a simple device used to compare the sense of brightness in the
two eyes. An investigation of brightness-sense with this device in normal
persons and patients with optic nerve disease, maculopathies, cataract, and
factitious visual impairment shows that brightness testing can provide
useful information supplementary and complementary to conventional clinical
and laboratory investigations. Impairment of brightness-sense was a
consistent finding among patients with optic neuropathies and, in some
cases, brightness testing appeared to be more sensitive than other
techniques in establishing the presence of disease. Brightness-sense was
also used to monitor the course of the patient's illness. Abnormalities
were also found among some patients with unilateral maculopathies, but
significant intereye differences in brightness-sense were not encountered
among normal persons or patients with cataracts. Patients with factitious
visual loss gave variable responses, and the nature of their disorder could
be identified by the inconsistency of their responses.
