Which condition might benefit from probing of the tear duct?

The condition that might benefit from probing of the tear duct is epiphora. Epiphora is characterized by excessive tearing due to an obstruction in the tear drainage system, which can prevent tears from properly draining away from the eyes. Probing the tear duct can help to clear the blockage, allowing tears to flow freely and reducing symptoms associated with excessive tearing.

In contrast, a chalazion, which is a blockage of oil glands in the eyelid, typically does not involve the tear drainage system directly and may be treated with warm compresses or, in some cases, surgical removal. A stye, which is an infection of an oil gland in the eyelid, also wouldn’t require probing of the duct but is usually managed with warm compresses and possibly antibiotics. Conjunctivitis, or inflammation of the conjunctiva, primarily involves the eye's surface and is usually treated with antiseptic or antibiotic drops rather than any intervention involving the tear ducts. Thus, probing is specific to issues like epiphora where tear drainage is impaired.