Meibomian gland Meibomian gland The Meibomian glands (often written with a small "m" and also called tarsal glands) are a holocrine type of exocrine glands, at the rim of the eyelids inside the tarsal plate, responsible for the supply of meibum, an oily substance that prevents evaporation of the eye's tear film. Meibum prevents tear spillage onto the cheek, trapping tears between the oiled edge and the eyeball, and makes the closed lids airtight. There are approximately 50 glands on the upper eyelids and 25 glands on the lower eyelids. Dysfunctional meibomian glands often cause dry eyes, one of the more common
Seam sealant a flexible waterproof "seal" by drying (dehydrating) in the case of water borne compositions, or thermoset irreversibly to a flexible adherent seam seal by going through an oven bake in the case of plasticized polyvinylchloride compositions. Most interior seam seals are not visible after the vehicle is finished, because they are covered by carpeting, interior roof headliner, or decorative trim panels. Exterior seam seals are always painted over and are referred to as "coach joint seals." The flat-stream application with many special solutions (special nozzles) was increasingly used as the most flexible procedure. Seam sealant Seam sealants are chemical coating