In vivo confocal microscopy was performed on the central cornea of both eyes of a patient with megalocornea and central mosaic dystrophy. In the stroma, starting just below Bowman's membrane, polygonal, moderately reflective areas of opacification separated by diagonal hyporeflective striations were observed. The opaque areas appeared smaller in the anterior stromal layers and seemed to get larger towards the posterior stroma. The epithelium, Bowman's membrane and endothelium appeared normal. In vivo confocal microscopy is helpful in evaluating the morphological characteristics of corneal dystrophies, degenerations or developmental abnormalities of the cornea, and may prove to be helpful in understanding their pathophysiology.