The tear film of the eye has an outer meibomian lipid layer (TFLL) that allows tears to spread across the eye and remain stable. Our Langmuir trough and other studies show that meibum forms duplex films that have unique physical properties not emulated by its major components: cholesterol and wax esters (WEs); and the surfactant (omega-acyl)-hydroxy-fatty acids (OAHFAs). Our X-ray reflectivity experiments show it has a 3-phase structure at low concentrations and some crystalline structures at high concentrations. We plan to seed meibomian lipid films with deuterated WEs and deuterated OAHFAs and use neutron scattering to determine the structure of the TFLL. It is proposed that the lipids will be anchored to the surface by the ester bond at low pressures, but these will leave the surface at higher pressures leaving OAHFAs at the surface anchored by the carboxyl group.