REIVEW OF LITERATURE maede sedghiyan Concern over the impact of television on students has fueled an energetic out pouring of research. Academic called upon as impartial referees in the “effects debate” have decades of empirical studies as well as a growing number of literature reviews that attempt to provide stateof-the-art synthesis of what we know about TV effects (Robert & bachen 1981 ;Liebert & Schwartzberg 1997; Weiss 2001; Tannen Baum & greenberg 2003).
Studies show that long period of television may hamper development of the pre-frontal cortex -the area of the brain responsible for planning ,organizing and sequencing behavior for self control, moral judgment and attention (Abell). TV viewing may replace activities that we know help with school performance such as reading doing homework pursuing hobbies and getting enough sleep. one research study found that effects of TV on education were long term.
The study found that watching TV as a student affected educational achievement( Van der Molan JH, Bushman BJ Association of television viewing with poor educational achievement. j pediatr. 2008 sep;153(3) :420-4. Epub 2008 Apr 28). a recent study conducted in Australia found that children who spend more time in front of television and computer screens have narrower blood vessels in their eyes. They study randomly selected school students in Sydney(Nicholas Baklar 2011) According to Dr. Annand Shroff 2009 ,TV should be watched from a distance of 4 meters or more.
Article” Elementary School Age Children and Their Eyes” suggested that children should be sited at least 3 meters(8 to10 feet) away from the television screen. Sharma Seema 2010 Who explored effect of television watching on vision of school children in rural Haryana, suggested the distance between eyes and the television screen should be always 6-8 times of the size of television screen. In this study, it was observed that prevalence of defective vision was more in cases of longer duration of TV watching , but the association of duration was not found to be significant with defective vision.
A QNRF-funded project, involving participants from Hamad medical corporation, Weill Cornell medical college in Qatar and the university of Westminster in London 2011, examined a sample of 2467 school children in Qatar to determine how prolonged hours in front of TV and computer screens affected levels of obesity and low vision. The students, aged 9-16 years, were interviewed face to face to complete a specially-designed questionnaire.
Eye examinations were carried out using a slit lamp, and visual acuity with Tumbling E chart at distance of 6 meters. Finally since there is a paucity of research in this issue in Iran, this study is aimed at analyzing impact of watching TV on vision of secondary school students in Taybad. In other words, it seeks to reveal whether students watching television too much have less vision than the others or not. To this end, this study was implemented in order to understand how much it can decrease their vision. REIVEW OF LITERATURE maede sedghiyan