Chalazion is characterised by either a quiet non-tender, or a tender, red, swollen, and warm bump on the eyelid. It is primarily caused by a blockage in one of the many oil glands of the eyelid, known as the meibomian glands.
This blockage occurs due to factors such as inflammation, bacterial infection, and the thickening of oil secretions. The lump may grow in size over time and cause discomfort or mild pain, or acute pain if it becomes very inflamed or infected. In some cases, it may also cause blurry or obstructed vision if it affects the position of the eyelid or puts pressure on the eye.