Fundus (eye)

The fundus of the eye is the interior surface of the eye, opposite the lens, and includes the retina, optic disc, macula, and posterior pole. The fundus can be viewed with an ophthalmoscope. The term may also be inclusive of Bruch's membrane and the choroid.

The eye's fundus is the only part of the human body where the microcirculation can be observed directly. The diameter of the blood vessels around the optic disc is about 150 μm, and an ophthalmoscope allows observation of blood vessels with diameters as small as 10 μm.

Diagnosis
Medical signs that can be detected from observation of eye fundus include haemorrhages, exudates, cotton wool spots, blood vessel abnormalities (tortuosity, pulsation and new vessels) and pigmentation.