US Patent 7758883 Three layer artificial tear formulation

An artificial tear film over the surface of an eye having a first layer in direct contact with the ocular surface, an aqueous layer over the first layer, and a layer of a phospholipid over the aqueous layer. The first layer has polyvinyl alcohol, polyvinyl acetate, and polyvinyl pyrrolidone. The phospholipid is derived from Amisol® Clear. The artificial tear film is effective in significantly prolonging the tear break up time in patients with dry eye syndrome.