The fundus of the eye is the interior surface of the eye, opposite the lens, and includes the retina, optic disc, macula and fovea, and posterior pole. The fundus can be examined by ophthalmoscopy and/or fundus photography. The term fundus may also be inclusive of Bruch's membrane and the choroid.
The color of the fundus varies both between and within species. In one study of primates the retina is blue, green, yellow, orange, and red; only the human fundus (from a lightly pigmented blond person) is red. The major differences noted among the "higher" primate species[clarification needed] where size and regularity of the border of macular area, size and shape of the optic disc, apparent 'texturing' of retina, and pigmentation of retina.