why are people experiencing computer headaches?

probable reason for your teary eye is eye strain, since you are spending really a lot of time on computers, to release your eye strain you can do palming exercise: vigorously rub your hands and when they are warm place your palms on your eyes and dont press your eye balls, you can repeat it for 3-4 times, i think this will really help help you

A headache is a condition of pain in the head; sometimes neck or upper back pain may also be interpreted as a headache. It ranks amongst the most common local pain complaints. Headaches have a wide variety of causes, ranging from eye strain, sinusitis, migraine and tension to life-threatening conditions such as encephalitis, meningitis, cerebral aneurysms, and brain tumors (although more than 95% of headaches are not life-threatening). When the headache occurs in conjunction with a head injury the cause is usually quite evident; however, many causes are more unclear. The most common type of headache is a tension headache which may be cause by posture. Some experience headaches when dehydrated, or suffering from caffeine withdrawal symptoms. Headaches may also be caused in some people by certain foods, such as peanuts, or food additives, such as tartrazine. They may also be caused by fumes, such as from a faulty heating boiler or from vehicles. Using computer could lead to lot of tension and pain in eyes, which ultimately leads to those head aches mentioned earlier :)

Most of the headaches aer caused by eye strain. A rough guide line would be around half an hour sitting at the screen, then walk away for a while.

i heard about the radiation but i think your eyes will get tired if you spend long enough in the front of the comp, decrease your brightness level or take a rest every 2 hours or so.