**tetrahydrozoline**: C13H16N2
[Tetrahydrozoline] or tetryzoline is a drug / chemical compound mainly used in [eye drops] and nasal sprays. Patented in 1954 and came into medical use in 1959. In many eye drops, it constricts [ocular] blood vessels to reduce redness. Tetrahydrozoline is surprisingly toxic and causing dizziness if ingested orally.
*"[Visine] with tetrahydrozoline relieves, soothes, refeshes morning [irritated eyes] and gets [the red] out!"*
*(<http://tetrahydrozoline.urbanup.com/14658588>)*
