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 Mind's Eye & Mission of the Viyrans audio dramas "Urgent Calls", "Urban Myths" and "The Vanity Box". This story marks the first appearance of the Viyrans for Big Finish. They first appeared in the short story "No One Died", also written by Nicholas Briggs, featuring the Tenth Doctor and published in the 2007 Doctor Who Storybook. The Viyrans return against the Sixth Doctor in "Patient Zero". The Mind's Eye & Mission of the Viyrans The Mind's Eye is a Big Finish Productions audio drama based on the long-running British science fiction television series "Doctor Who". It is a three-part story written by Colin Brake and was released