keep one's eyes peeled

keep one's eyes peeled или keep one's eyes skinned  {v. phr.},  {informal}

Внимательно следить, быть настороже; все время смотреть во все глаза.

The bird-watcher kept his eyes peeled for bluebirds.

When the boys walked through the roads, they kept their eyes skinned for snakes.

Ср.: EYES OPEN (1), EYE OUT.