Tear film and ocular surface

The **tear film and ocular surface** are a tightly integrated anatomical and functional unit critical for vision, comfort, and protection of the eye. The tear film is comprised of three layers—lipid (outer), aqueous (middle), and mucin (inner)—spanning the corneal and conjunctival epithelium, and maintained through secretions of the lacrimal and meibomian glands. This multilayered structure provides lubrication, stability for optical refraction, defense against pathogens, and nourishment to ocular tissues. Dysfunction of any component can lead to **dry eye disease**, impaired vision, increased infection risk, and ocular discomfort. Therapeutic approaches focus on supplementing or restoring tear film integrity and treating underlying glandular or surface pathology, rather than targeting a specific molecule or receptor[1][3][5].

Other names

Ocular tear filmPre-corneal tear filmOcular surface

Drug supplementation of tear constituents (lubrication, hydration)[1][5] Anti-inflammatory modalities suppressing ocular surface immune activation[1] Stimulation of normal tear secretion and Meibomian gland function[1][5] Direct antimicrobial action (for infection)[5]