Postoperative brain damage is a major sequela of cardiovascular surgery. Different methods-such as transcranial Doppler imaging, carotid echography, and fluorescein angiography-can be used to monitor cerebral blood flow, but they present specific limitations.High-resolution color Doppler imaging of the ophthalmic artery is a useful, noninvasive, and inexpensive technique for the evaluation of cerebral blood flow during cardiac surgery; signal changes can represent hypoperfusion of cerebral vessels and can thereby indicate inadequate cerebral perfusion during cardiac surgery, especially surgery of the aortic arch.