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
Catholic theology of the body God in his image. This is considered important even today, as the existence of a soul is the basis for much Church teachings on the human body, in areas such as abortion. Ambrose of Milan and Augustine of Hippo applied these views in their teachings on the human body, virginity and celibacy. Thomas Aquinas developed a systematic view, which dominated Church teachings and ecumenical councils including Vatican II. All recent popes contributed from different angles to the theology of the body. Current issues include the dignity of the body in light of its divine origin and destination, its eventual resurrection;