A 44-year-old man presented with bilateral punctate corneal epitheliopathy complaining of worsening discomfort and photophobia over the previous several days. He was HIV positive, had a recent CD4 count of 4 x 10(6), and had started on highly active antiretroviral therapy (HAART) 14 days prior. Failure to respond to lubricant therapy with worsening of the epitheliopathy over the following week led to corneal biopsy and diagnosis of corneal microsporidiosis. Investigations revealed that he remained anergic and that his CD4 count had not changed. However, his viral load had decreased by at least 0.9 log10 units since HAART intiation. Therapy with albendazole led to complete resolution of his pre-existing symptoms of nasal congestion and epistaxis, as well as all recently occurring ocular signs and symptoms. It was concluded that the microsporidiosis was a pre-existing opportunistic infection, whose presence was unmasked by a form of immune restoration induced by HAART.