A chalazion is a swelling in the eyelid caused by inflammation of one of the small oil-producing glands located in the upper and lower eyelids. A chalazion is sometimes confused with a stye, which also appears as a lump in the eyelid. However, a stye is an infection of a lash follicle and forms a red, sore lump. Chalazions tend to occur farther from the edge of the eyelid than styes and tend to "point" toward the inside of the eyelid. Sometimes a chalazion can cause the entire eyelid to swell suddenly, but usually there is a particular tender point.
When a chalazion is small and without symptoms, it may disappear on its own. If the chalazion is large, it may cause blurred vision. Chalazions are treated with any or a combination of the following methods:
Chalazions usually respond well to treatment, although some people are prone to recurrences. If a chalazion recurs in the same place, your ophthalmologist may suggest a biopsy to rule out problems that are more serious.