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 Heron in "The Eye of the Heron" are themes common to much of Le Guin's fiction and include the social constructions of gender, interactions between individuals from different societies, intra-actions within societies, and contact with that which is perceived as alien or other. The novel also explores different forms of social and political organization by juxtaposing pacifist anarchism with violent oligarchy. The characters' metaphorical internal journeys are reflected in literal external journeys throughout the plot. When asked, in a 1995 interview, what role the feminist movement had played in her writing, Le Guin situated "The Eye of the Heron" in the