The initial step in the differential diagnosis of an enlarged eye is to determine whether an intraocular mass is present. The globe may be expanded by a mass, seen mainly in children with retinoblastoma. Buphthalmos with or without neurofibromatosis also enlarges the eye. Diffuse enlargement may be associated with a connective tissue disorder or be related to axial myopia. Focal enlargement represents staphyloma, which can be unilateral or bilateral. In the presence of one small eye, the normal-sized eye may be incorrectly diagnosed as large.