"Studies have indicated 70 percent to 90 percent of people who use computers extensively, whether for work or play, have one or more symptoms of computer vision syndrome. The effects of prolonged computer use are not just vision-related. Complaints include neurological symptoms like chronic headaches and musculoskeletal problems like neck and back pain. The report’s authors, Tope Raymond Akinbinu of Nigeria and Y. J. Mashalla of Botswana, cited four studies demonstrating that use of a computer for even three hours a day is likely to result in eye symptoms, low back pain, tension headache and psychosocial stress. Still, the most common computer-related complaint involves the eyes, which can develop blurred or double vision as well as burning, itching, dryness and redness, all of which can interfere with work performance."