How can I differentiate between a chalazion and a hordeolum during a clinical examination?

During a clinical examination, a chalazion typically presents as a painless, firm, localized swelling of the eyelid that is usually non-tender and has a gradual onset ².

In contrast, a hordeolum (stye) is generally painful, tender, and has a more acute onset, often associated with localized erythema and swelling of the eyelid margin ³.

A chalazion tends to be a deeper, more indurated lump that may be located away from the eyelid margin, whereas a hordeolum is often situated at the eyelid margin, involving the eyelash follicle or meibomian gland ²,³.

Additionally, a hordeolum may show signs of active infection such as pus or a pustule, while a chalazion usually does not have purulent discharge ²,³.