Hypopyon

Hypopyon is pus in the eye.

It is a leukocytic exudate, seen in the anterior chamber, usually accompanied by redness of the conjunctiva and the underlying episclera. It is a sign of inflammation of the anterior uvea and iris, i.e. iritis, which is a form of anterior uveitis.

Differential diagnosis
Hypopyon can also be present in a corneal ulcer, particularly of fungal etiology like Aspergillus and Fusarium sp., Behcet's disease, endophthalmitis, and panuveitis/panophthalmitis.