Abstract: There are many causes of dry eye, and its main feature is the imbalance of tear film homeostasis. With the increase in knowledge regarding the pathophysiology of dry eye, it is found that the maintenance of tear film homeostasis benefits from the normal operation of each component of lacrimal function unit. Lacrimal functional unit comprises cornea, conjunctiva, lacrimal gland, meibomian glands and the neural network that connects them. It controls secretion of the tear film in a regulated fashion. Compromise in one or more components can result in homeostasis disruption of ocular surface leading to dry eye disease. Therapy targeting cornea includes autologous serum, nerve growth factor, contact lens and anti-inflammatory treatment; therapy targeting conjunctiva includes vitamin A, anti-inflammatory treatment and operation. Therapy targeting lacrimal gland includes cyclosporine A, androgen and regeneration of lacrimal gland; therapy targeting meibomian glands includes warm compresses, manual lid massage and ω -3 fatty acid. Therapy targeting tear film includes compensation of tear, stimulating tear production, controlling tear evaporation and regulating excessive nasolacrimal drainage. Understanding the physiological function and pathological changes of the main components of lacrimal function unit is helpful to provide ideas for personalized treatment of dry eye. (Int Rev Ophthalmol, 2021, 45: 135-140)

Key words: dry eye, ocular surface, lacrimal film homeostasis, tear film homeostasis