An ophthalmic fluid containing at least one triglyceride, diglyceride, or monoglyceride which is chemically similar or compatible with compounds found naturally in the lipid layer of the tear film of an ocular substrate. Preferably the glycerides are derived from a fatty acid containing at least one unsaturated bond in a cis-configuration in the fatty acid residue. The ophthalmic fluid is arranged in use to provide a protective film across a tear film of an ocular substrate. Furthermore, the ophthalmic fluid is also arranged in use to provide a protective film intermediate a lipid layer of the tear film of the ocular substrate and a contact lens.