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

It is as well to keep one's eyes open, constable, when investigating a case like this.'

From The Triumphs of Eugène Valmont by Barr, Robert

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 Farthest North Being the Record of a Voyage of Exploration of the Ship 'Fram' 1893-1896 by Nansen, Fridtjof

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 Treasure of Kings Being the Story of the Discovery of the \"Big Fish,\" or the Quest of the Greater Treasure of the Incas of Peru. by Gilson, Charles

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.

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)