The tear film on the surface of the eye is a critical component of maintaining vision. Tears nourish and lubricate the surface of the eye as well as wash away debris. A smooth, balanced tear film (consisting of water, oil and mucus) also allows light to enter the eye in an optimal fashion. If there is a disturbance of the tear film, patients will often experience tearing, burning, irritation and most importantly blurred vision. Patients who experience tearing, or epiphora, either have a problem with tear production or tear drainage, including dry eyes, blepharitis, eyelid malposition (ectropion, entropion, eyelid retraction), nasolacrimal duct(tear duct) obstruction (congenital and acquired).