Serum tears are eye drops made from a patient's own blood and is a therapeutic treatment used by eye doctors to treat damaged eye surfaces namely in severe dry eye disease. They are preservative-free, microfiltered, custom-made eye drops that incorporate the components of patients' blood that are composed of a complex mix of growth factors, proteins, antioxidants and lipids. This creates tears are akin to the components of natural human tears and may provide a more effective replacement than over-the-counter artificial tears.