Strabismus Essay -- Biology Essays Research Papers

Strabismus A camera lens focuses patterns of light onto film which records the image exactly. If the lens is out of focus or partially covered, a b lurry or obscured picture will result. The film is a recording device, it does not interpret and select what it portrays. Images from a camera are objective in a very literal sense. Seeing, however, is not such a seamless process. Our eyes work similarly to a camera in that they have a lens which focuses a real image on our retina, a light sensitive sheet of cells. This retinal image is a portrayal of the world as it truly is. The image which we see, however, is not this image. By considering a normal vis ual property as well as an uncommon ocular disorder the process of formulating our visual sense will be investigated. There is a difference between the picture recorded on film and that recorded by our brains. For purposes of this paper, the term "retina l image" is used as an analogy to a photographic image (one without interpretation by the brain ). The phrase "brain image" refers to the retinal image post-brain interpretation. The brain image is the image which would be described by the person, the imag e which is thought of as seeing. This phenomena of brain interpretation is easily demonstrated by discovering one's blind spot. (A good self experiment is described at 1) The blind spot results from an area of the retina which does n ot have photoreceptor nerve cells, the optic nerve head. Yet, even without this seemingly vital information, the brain is able to supply us with a complete brain image. The brain has filled in the blind spot with an image which it believes makes sense. Ha ving explored the blind spot, one can understand that what is captured in the brain image m... ...have been ignored is forced to develop. Adult onset strabismus, however, results in double vision because the brain can not simply ignore the one image that does not make sense. This type of strabismus can not be treated with patching, as their brains have already developed a patte rn which uses both eyes to comprise the brain image. (4) (5) This exploration of strabismus has shown that the brain is a very active participant in determining our perception of the world around us. Visual informati on received by the eye is only part of the story, the brain takes these images and selects what is useful, discarding (strabismus) as well as adding (blind spot) information, thus, constructing our visual experience. Internet Sources: http://serendip.brynmawr.edu/bb/blindspot1.html http://www.hhmi.org/senses/b410.html http://www.seekwellness.com/index.htm