Left eye watering like crazy!! didn't get anything in it. only wear one contact (right eye). left eye has been watering for 2 days. what could it be?

Can be different: reasons, and if it's lasting this long, you really should see an eye doctor!S/he will need to examine you under a slit lamp microscope and look at the puncta (hole) that drains your tears on that side and see if there's anything blocking it? It normally doesn't tear spontaneously.S/he will check your cornea too, and see if there's anything that may be irritating your eye, or eyelids.Is it itching?