A "reverse hypopyon" can form when emulsified silicone oil used during vitreoretinal surgery enters the anterior chamber of the eye. The silicone oil floats in the aqueous to look like a layered hypopyon in the upper portion of the anterior chamber. Also visible in this photograph is an inferior peripheral iridectomy and sectoral iris nevus.
Ophthalmic Atlas Images by EyeRounds.org, The University of Iowa are licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.