What is a chalazion?

• A. An acute purulent eyelid infection.
• B. A malignant eyelid tumor.
• C. Inflammation of the iris.
• D. An inflamed nodule that develops on the eyelid, often caused by blocked glands.

Answer: (D)

Chalazion is a chronic, noninfectious blockage of a meibomian gland in the eyelid that leads to a granulomatous inflammation. It presents as a painless, firm, rubbery nodule on the eyelid, often the upper lid, which may slowly enlarge. This contrasts with a stye, which is an acute, painful, purulent infection of eyelid glands. It also isn’t an intraocular problem like iris inflammation (iritis), which causes eye pain and photophobia, or a malignant eyelid tumor, which tends to have irregular borders and progressive changes over time. The description “an inflamed nodule that develops on the eyelid, often caused by blocked glands” best fits chalazion because it captures the typical location, painless nodular swelling, and the underlying mechanism of duct obstruction.