What is viscosity and Density of meibomian lipid?

Viscosity is a measure of a fluid's resistance to flow, while density refers to the mass per unit volume of a substance. Meibomian lipids, secreted by the meibomian glands in the eyelids, have varying viscosity and density depending on their composition, which primarily includes long-chain fatty acids and wax esters. These properties are crucial for maintaining the stability of the tear film and preventing evaporation of the tears. Specific values can vary, but generally, meibomian lipids exhibit higher viscosity compared to typical oils due to their complex structure.