Examination of the right eye showed it to be structurally sound in all regards. The left eye was injected, and biomicroscopy revealed slight flare and some inflammatory cells in the anterior chamber. Pigment deposits on the anterior lens surface and posterior synechiae were present (Fig. 1). The intraocular pressure was 18 mmHg on the right and 24 mmHg on the left. The left lens was clear, but immediately behind the lens there was a grey-white intraocular membrane or mass associated with an array of dilated vascular channels and pigment deposits. The ocular fundus could not be visualised.Systemic examination was negative, with no evidence of regional or generalized lymphadenopathy, skin lesions, arthropathy or hepatosplenomegaly.The right visual field was normal (Goldmann perimetry) but it was not possible to obtain a plot on the left side. Electroretinography showed a normal B wave amplitude on the right side, but recordings on the left side were extinguished, even to a bright flash. Fluorescein angiography (Fig. 2) confirmed the presence of numerous dilated shunt-like blood vessels within the retrolenticular mass. These blood vessels filled rapidly in the early phases of angiography; the major channels remained competent, while the smaller vessels leaked dye, causing the retrolenticular mass to become hyperfluorescent by the later angiographic frames. Some of the large