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
Sociology of the body Sociology of the body Sociology of the body is a branch of sociology studying the representations and social uses of the human body in modern societies. According to Thomas Laqueur, prior to the eighteenth century the predominant model for a social understanding of the body was the "one sex model/one flesh model". It followed that there was one model of the body which differed between the sexes and races, for example, the vagina was simply seen as a weaker version of the penis and even thought to emit sperm. This was changed by the Enlightenment. In the sixteenth century, Europe