Diurnal variation in the dimensions of the anterior chamber.

Anterior chamber depth and volume were measured photogrammetrically on a diurnal basis in 38 eyes from 21 normal subjects. Significant diurnal variation in anterior chamber dimensions was demonstrated. Anterior chamber depth and volume measurements were significantly lower in the evening than in the morning, with particular emphasis on the periphery of the anterior chamber. Axial depth decreased by 2.1%; peripheral depth, by 21.1%; and anterior chamber volume, by 5.7%.