'eye-opener' originates from the combination of 'eye' and 'open,' where 'eye' refers to the organ of sight and 'open' means to reveal or make visible.

'eye-opener' was first used in the 19th century to describe a drink taken to wake someone up, and eventually evolved to mean something that reveals or enlightens.

Initially, it meant 'a drink to wake someone up,' but over time it evolved into its current meaning of 'something that reveals or enlightens.'