Human eye of the size of the pupil, regulation and suppression of the hormone melatonin and entrainment of the body clock. The eye is not shaped like a perfect sphere, rather it is a fused two-piece unit, composed of the anterior segment and the posterior segment. The anterior segment is made up of the cornea, iris and lens. The cornea is transparent and more curved, and is linked to the larger posterior segment, composed of the vitreous, retina, choroid and the outer white shell called the sclera. The cornea is typically about 11.5 mm (0.3 in) in diameter, and 1/2 mm (500
The Eye of the Sibyl The Eye of the Sibyl "The Eye of the Sibyl" is a science fiction short story by American writer Philip K. Dick. It was written sometime around 1975, but not published until 1987 when it was included in volume 5 (subtitled "The Little Black Box") of "The Collected Stories of Philip K. Dick", and has been reprinted since in other editions of this book such as the U.S. edition "The Eye of the Sibyl and Other Stories" . This is said to have been Dick's first piece of fiction for publication after his "2-3-74" experience that was the basis for