You see, her eyes are open.
Ay, but their sense is shut.
What is it she does now? Look how she rubs her hands.
It is an accustomed action with her, to seem thus washing her
hands: I have known her continue in this a quarter of an hour.
Yet here's a spot.
From the above situation it comes to mind that yet Lady Macbeth thought in her mind that spot of her action can be got rid of just with a little water. We generally think that we see with our eyes. Lady Macbeth's eyes are open but she cannot see. It symbolises a cunning man with high ambition cannot judge what is right and wrong.
However, she seems to repent for her past misdeeds, not truly but to get rid of present situation.
She carries a light in her hand and yet without her inner light. Its pretensious.