Cysts rarely develop within the cornea or sclera of children with no previous history of trauma or surgery. Primary corneoscleral cysts may arise from proliferation of anomalously situated epithelial or endothelial cells. We report the case of a 2-year-old girl with a primary enlarging cyst situated at the limbus of her left eye. Optical coherence tomography was used to determine whether there was any communication between the cyst and the anterior chamber and to help plan appropriate management.