Nystagmus 5 : Involuntary, rapid, rhythmic movement (horizontal, vertical, rotary, mixed) of the eyeball, usually caused by a disorder of the labyrynth of the inner ear or a malfunction of the central nervous system
International Union of Pure and Applied Chemistry IUPAC, Glossary for Chemists of Terms Used in Toxicology, Prepared for publication by J.H. Duffus, NC., USA 1993. http://www.inchem.org/documents/harmproj/harmproj/ harmproj1.pdf & http://old.iupac.org/reports/1993/6509duffus/c.htm l, (IUPAC/ Tox - Amer) {107}