see something out of the corner of your eye

From King Dictionary of Contemporary Englishsee something out of the corner of your eyesee something out of the corner of your eyeNOTICEto notice something accidentally, without turning your head towards it or looking for it Out of the corner of her eye she saw the dog running towards her. corner
Examples from the Corpus
see something out of the corner of your eyeOut of the corner of her eye, she saw a man running out of the store.