keep one's eyes open

Idioms  

1. Also,. Be watchful and observant. For example, We should keep our eyes open for a change in the wind's direction, or Keep your eyes peeled for the teacher. The first phrase dates from the late 1800s; the second and third, both colloquial and alluding to the lids not covering the eyes, date from the mid-1800s and 1830s, respectively.

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Example Sentences

Of course, it was needful to exercise a certain amount of discretion, to keep one's eyes open whilst in the water; and I do not say that there was no danger present.

From Project Gutenberg

“It seems worth while to keep one’s eyes open,” she laughed, and began to shuffle with the toe of her shoe in the dusty street.

From Project Gutenberg

Thou knowest well how to furnish a guard-room when one is required to keep one's eyes open and one's spirits up.

From Project Gutenberg

From the snow-hut observatory, or even at a lesser distance, the Fram is invisible, and it is almost impossible to keep one’s eyes open, owing to the blinding snow.

From Project Gutenberg

One had to keep one’s eyes open there, for they were every bit as brave as we were.

From Project Gutenberg