Chalazion or Stye

There are approximately 30 glands in the upper and lower eyelids that are responsible for producing oil that stabilizes your tear film. These glands are called meibomian glands. The oil produced by meibomian glands protects your tears from evaporating. Occasionally, one of these meibomian glands can become blocked and backfill causing a red swollen lump on your upper or lower eyelid called a chalazion.