to see sth by accident or not very clearly because you see it from the side of your eye and are not looking straight at it
see sth out of the corner of your eye
to see sth by accident or not very clearly because you see it from the side of your eye and are not looking straight at it
Out of the corner of her eye, she saw him coming closer.
Definiciones del Oxford Advanced Learner's Dictionary, 9.ª edición