Question: Does sitting too close to the television really ruin my eyes? And, similarly, does sitting in front of a computer screen lead to eye problems?
Answer: The greatest problem with sitting close to the TV might be aggravation from the person whose view you are blocking! The question of whether too much "close work" is harmful to the eyes is not a new one. It was actually proposed as far back as the 17th century, at a time when scientists were calculating the paths of planetary motion. They conducted their research using the principles of physics and optics, which apply to both astronomy and the investigation of light paths into the eye. German mathematician and astronomer Johannes Kepler, who was the first to correctly identified the paths of some of the planets, claimed that close work during adolescence resulted in shortsightedness (myopia). He considered the excessive time reviewing data on planetary motion to be an explanation of his own myopia
Because myopia requires prescription glasses, it may have been assumed that close work "ruins" the eyes. This claim continued for centuries; in fact, watching TV and looking at a computer screen have actually been added to the list of risk factors for eye damage in the form of myopia.
This theory was accepted for many years. However, evidence was published in February, 2009, that it is unfounded. Watching TV from a close distance, or spending long hours in front of a computer screen, will not result in shortsightedness.
The main risk factor for shortsightedness is genetics, with a greater risk if both parents are shortsighted. Watching TV or looking at a computer screen may cause eye strain, the signs of which include blurred vision and red or watery eyes. About 5 per cent of the population is light-sensitive, experiencing discomfort from flickering light of specific frequencies, colours and patterns. Some people get headaches from excessive time in front of the TV or computer. To avoid some of these problems, it is advisable not to watch TV in a dark room, to sit a little farther from the TV, to angle the computer screen straight ahead and to use an anti-glare screen. It is also important to go for regular eye exams and wear glasses if necessary. These strategies can help to prevent eye strain.
What about the risk of electromagnetic radiation on the eyes? Very close viewing of a TV or computer screen may slightly raise the temperature of eye tissue, but this increase is not as significant as the radiation emitted by mobile phones.
While we know there are disadvantages from hours spent in front of a TV or a computer, we now know that eye damage, and shortsightedness in particular, is not one of them.
Dr. Carol Westall is a University of Toronto professor of ophthalmology and director of the visual electrophysiology unit and a senior associate scientist at the Hospital for Sick Children in Toronto.