The case histories and eye findings of 2 siblings of a non-sanguinous marriage are reported. The first child, a girl, had the typical findings of a unilateral congenital glaucoma. Her brother had an enlarged unilateral cornea (13 mm) without Descemet breaks, and normal intraocular pressure on repeated follow-up examination over 4 years. Gonioscopy showed numerous iris processes covering the iridocorneal angle. Fundus examination revealed a cup-disc ratio of 0.4 in the affected eye and 0.1 in the normal eye. Patients whose clinical picture resembles that of our second patient should be classified as having incomplete or abortive congenital glaucoma; such patients may develop raised intraocular pressure at a later stage. The term megalocornea should be reserved for eyes with enlarged cornea, normal intraocular pressure, normal iridocorneal angles, no cup-disc asymmetry and no family history of congenital glaucoma.