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

A man had to know the surroundings well to find his way now; one had to feel -- it was impossible to keep one's eyes open.

From The South Pole; an account of the Norwegian Antarctic expedition in the "Fram," 1910-12 — Volume 1 and Volume 2 by Chater, Arthur G.

A man had to know the surroundings well to find his way now; one had to feel — it was impossible to keep one's eyes open.

From The South Pole; an account of the Norwegian antarctic expedition in the "Fram," 1910-1912 — Volume 1 by Chater, Arthur G.

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

From Out on the Pampas Or, The Young Settlers by Henty, G. A. (George Alfred)

I tell you one had to keep one's eyes open in those days.

From Captain Bayley's Heir: A Tale of the Gold Fields of California by Paget, H. M. (Henry Marriott)

There is something in the game of poker that will keep one's eyes open longer than will the fear of death, so the four kept on playing until time for luncheon.

From Tales of the Road by Crewdson, Charles N. (Charles Newman)