Tears are produced by the lacrimal gland located in the upper outer portion of each eye. Tears drain into a tear duct through a very small opening in the corner of your eye, near your nose. This opening is called the nasolacrimal duct. If this duct is blocked, the tears will build up and overflow onto the cheek.
Update Date 9/2/2014
Updated by: Franklin W. Lusby, MD, ophthalmologist, Lusby Vision Institute, La Jolla, CA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.