Figure 1. Fundus images from an eye subjected to successively increasing intraocular pressure. At normal pressure (10–20 mmHg) the pigs had a normal fundus with filled blood vessels. The filling of the blood vessels decreased and the fundus became paler as the intraocular pressure (IOP) increased. At an IOP of 80 mmHg, blood flow was completely inhibited. IOP is given with ±5 mmHg variability.