Uhthoff's symptom

Uhthoff's symptom 

Temporary blurring of vision occurring when there is an increase in body temperature (e.g. during or following exercise) in patients with multiple sclerosis, optic neuritis and other optic neuropathies. The symptom may also occur as a result of emotional stress, menstruation, increased illumination or a hot bath. Uhthoff's symptom is sometimes considered to be a prognostic indicator of multiple sclerosis in patients with idiopathic optic neuritis. Syn. Uhthoff's phenomenon; Uhthoff's sign; Uhthoff's syndrome.
Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann