in intraocular pressure diurnal variations

diurnal variations, in intraocular pressure

Normal intraocular pressure varies throughout the day within a range of about 4 mmHg, being higher in the morning than in the evening. In patients with primary open-angle glaucoma this range is greater. This variation must be taken into consideration when measuring intraocular pressure.
Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann