Category B - full version without watermark 1024x576 (check terms and conditions at www.teledesign.de) The embed version with watermark is free of charge. The intraocular pressure plays a central role for the spherical shape and the function of the eye. It is regulated by the aqueous humour in the front part of the eye. This watery substance is produced by the epithelium of the ciliar body and escapes through the pupil into the anterior chamber. From there it drains through Schlemm's canal into the vein system. The intraocular pressure results hence from the relation between production and drainage of the aqueous humour.