看 + 了 + Number + 眼
眼 (yǎn) is a measure word (classifier) used to count glances or looks. It appears in the common expression 看了一眼 (kàn le yī yǎn, "took a glance"), indicating a quick, brief look at something.
他朝我看了一眼,什么也没说。
tā cháo wǒ kàn le yī yǎn, shénme yě méi shuō.
He glanced at me and said nothing.
我只瞟了一眼,就认出他来了。
wǒ zhǐ piǎo le yī yǎn, jiù rèn chū tā lái le.
I only took a quick glance and recognized him right away.
她偷偷看了他一眼,脸红了。
tā tōutōu kàn le tā yī yǎn, liǎn hóng le.
She sneaked a glance at him and blushed.