The meibomian glands are specialized sebaceous glands located in the eyelids. They produce an oily substance called meibum, which is essential for maintaining the health of the tear film. This oil helps prevent tears from evaporating too quickly, ensuring that the eyes remain lubricated and comfortable. Each eyelid contains about 20 to 30 meibomian glands, which open at the eyelid margins. When these glands function properly, they contribute to clear vision and eye comfort. Dysfunction of the meibomian glands can lead to conditions like dry eye syndrome or meibomian gland dysfunction, causing discomfort and visual disturbances.