Working at a computer is a visually demanding task, often in a compromised visual environment. Various forms of visual and physical discomfort (and decreased performance) commonly occur. The most common include eye strain (sore eyes, eye fatigue, slowness in change of focus), eye irritation (burning, dryness, redness) headache, near blurred vision, glare sensitivity, neck, shoulder and back pain, repeated strain injury particularly of the wrist and reproductive hazards as a result of radiation from video display screens.