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
History of beliefs about the human body History of beliefs about the human body The human body has been subject of much debate. How people are defined, and what defined them – be it their anatomy or their energy or both – depends on culture and time. Culture not only defines how sex is perceived but also how gender is defined. Today gender, sex, and identity continue to be of much debate and change based on what place and people are being examined. The early modern idea of the body was a cultural ideal, an understanding and approach to how the body works and what place that