eye-opener

noun5

1. •
   Something that causes the eyes to open, or that opens the eyes.
2. •
   (informal) Something that provides a sudden insight, or makes something clear that was previously mysterious.
3. •
   (informal) A startling or shocking revelation.

   • A visit to the slaughterhouse was a real eye-opener to anyone who thought they understood where their food came from.
4. •
   (informal, euphemistic) A strong alcoholic beverage, especially one consumed in the morning.

   • As soon as I got on the plane I asked the flight attendant for an eye-opener, but all he had to offer was orange juice.
5. •
   (informal) An attractive woman.

   • Seems appropriate that Ann Miller should be in Columbia's "Reveille With Beverly." We've never seen anyone capable of "showing a leg" more attractively. At close range, too, she's an eye-opener. — 1943