What is "eye opener"

eye opener \eye opener\ n.

1. That which makes the eyes open, as startling news or occurrence; something which causes one to suddenly understand what was not previously known.

2. A drink of liquor, especially the first one in the morning. [U. S. Slang]

1. n. an alcoholic drink intended to wake one up early in the morning

2. something surprising and revealing

Eye Opener is a Canadian experimental drama television series which aired on CBC Television in 1965.