Thealoz Duo is a sterile, preservative-free, hypotonic, pH-neutral aqueous ophthalmic solution. Its main components are trehalose, a disaccharide present in many plants and animals, and sodium hyaluronate, a polysaccharide naturally present in the eye. The physical-chemical characteristics of trehalose give it protective, antioxidant and moisturizing properties. Sodium hyaluronate has unique water-retaining properties that result in increased hydration and lubrication of the corneal surface, and its bioadhesive properties provide better adhesion of the product to the surface of the eye, which allows for long-lasting relief and a reduction in the time required for corneal healing. Thus, the combination of trehalose with sodium hyaluronate ensures protection, hydration and lubrication of the ocular surface for a longer period of time and with maximum comfort.