Search results
Results from the WOW.Com Content Network
Diagram of a human eye; note that not all eyes have the same anatomy as a human eye. The mammalian eye can also be divided into two main segments: the anterior segment and the posterior segment. [10] The human eye is not a plain sphere but is like two spheres combined, a smaller, more sharply curved one and a larger lesser curved sphere.
The size of the eyes in mammals is relatively small; in humans, eye weight is 1% of the mass of the head, while in a starling it reaches 15%. Nocturnal animals (for example, tarsiers) and animals that live in open landscapes have larger eyes.
Almost all mammals have brown or darkly-pigmented irises. [34] In humans, brown is by far the most common eye color, with approximately 79% of people in the world having it. [35] Brown eyes result from a relatively high concentration of melanin in the stroma of the iris, which causes light of both shorter and longer wavelengths to be absorbed. [36]
Eyes and other sensory organs probably evolved before the brain: There is no need for an information-processing organ (brain) before there is information to process. [21] A living example are cubozoan jellyfish that possess eyes comparable to vertebrate and cephalopod camera eyes despite lacking a brain.
This type of eye is common in mammals, including humans. The simplest eyes are pit eyes. They are eye-spots which may be set into a pit to reduce the angle of light that enters and affects the eye-spot, to allow the organism to deduce the angle of incoming light. [1] Eyes enable several photo response functions that are independent of vision.
Ileum, caecum and colon of rabbit, showing Appendix vermiformis on fully functional caecum The human vermiform appendix on the vestigial caecum. The appendix was once believed to be a vestige of a redundant organ that in ancestral species had digestive functions, much as it still does in extant species in which intestinal flora hydrolyze cellulose and similar indigestible plant materials. [10]
Superficial anatomy of female and male human body Surface projections of the major organs of the trunk, using the vertebral column and rib cage as main reference points of superficial anatomy Superficial anatomy or surface anatomy is important in human anatomy being the study of anatomical landmarks that can be readily identified from the ...
The functioning of a camera is often compared with the workings of the eye, mostly since both focus light from external objects in the field of view onto a light-sensitive medium. In the case of the camera, this medium is film or an electronic sensor; in the case of the eye, it is an array of visual receptors.