一眨眼

一眨眼:

Literally means:

at blink of an eye

Actually means:

This phrase originally refers to the time of a blink of the eye and indicates the flying of the time. It is rhetoric exaggeration about people's subjective feeling and judgment of the time flying.

眨一下眼睛的时间，形容极短、极快的时间。是夸张的说法。时间的短和快完全是说话人的感觉和判断。