Eye surface lubrication

Eye surface lubrication" refers to the physiological process by which the front of the eye—primarily the cornea and conjunctiva—is kept moist, smooth, and protected from friction. This is achieved through maintenance of an intact tear film composed of three layers: * The mucous layer produced by conjunctival goblet cells, * The aqueous layer secreted by lacrimal glands, * The lipid layer produced by meibomian glands.[2] Mucins—large glycosylated proteins such as MUC5AC (secreted) and membrane-associated mucins like MUC1, MUC4, and MUC16—play critical roles in maintaining hydration, reducing friction during blinking, clearing debris/pathogens from the ocular surface, and preventing cell adhesion.[1] Disruption in any component can lead to dry eye symptoms or increased risk for infection. Artificial lubricants ("artificial tears") are commonly used therapeutically but do not represent interaction with a single molecular target; instead they supplement or mimic natural tear components using polymers such as carboxymethylcellulose or hyaluronan.[3][4]

For drugs used in this context (artificial tears/lubricants): Provide moisture and lubrication to the ocular surface by mimicking or supplementing natural tear film components. Form protective layers over the cornea and conjunctiva to reduce friction and prevent drying.[1][2][3]