Epiphora refers to the overflow of tears onto the face due to inadequate drainage through the nasolacrimal system.
It is not caused by excessive production but by obstruction to the outflow of tears.
Conditions like blockage of the lacrimal duct or punctum lead to epiphora.
Steven’s–Johnson’s syndrome and sensory stimulation are not the definitions of epiphora.
Therefore, the correct answer is obstruction to outflow of tears.