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

One cannot keep one's eyes open very long without winking, but the stranger did.

From The Ape, the Idiot & Other People by Morrow, W. C.

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.

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.

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

One cannot keep one's eyes open very long without winking, but the stranger never winked at all.

From The Best British Short Stories of 1922 by Cournos, John