The fovea centralis lacks rods and this part of the eye becomes practically color blind at very low intensities of light.
"The Nature of Animal Light"
E. Newton Harvey
Langenbeck states that the fascia is constantly protruded as a covering to this hernia: "Quia hernia inguinalis interna non in canalis abdominalis aperturam internam transit, tunicam vaginalem communem intrare nequit; parietem autem canalis abdominalis internum aponeuroticum, in quo fovea inguinalis interna, et qui ex adverso annulo abdominali est, ante se per annulum trudit."
"Surgical Anatomy"
Joseph Maclise
The eye, whose general structure is sufficiently described in all standard physiologies, consists of a visual apparatus designed to bring the images of objects to a clear focus on the retina at the fovea, or area of clearest vision, near the point of entrance of the optic nerve.
"The Mind and Its Education"
George Herbert Betts