They lubricate the eyes and help to maintain moisture.
Artificial tears are available without a prescription and there are many brands.
They are also available in varying viscosity and in ointment form. Preservative-free preparations are used in those individuals who are sensitive to preservative or who use tears more frequently than every two hours. Conserving the tears Tears drain out of the eye and into the nose. If low tear production is a problem then preventing tears drainage will help tears last longer. In a person with normal production, blocking tear drainage would cause the tears to spill over onto the cheek.