Who can tell me what is asthenopia and will kids have asthenopia?What`s the symptom of asthenopia ?

Asthenopia or eye strain is an ophthalmological condition that show itself through nonspecific symptoms such as fatigue, red eyes, pain in or around the eyes, blurred vision, headache and occasional double vision. Symptoms often occur after reading, computer work, or other activities that involve tedious visual tasks.

Hi, do you have any idea about how to avoice asthenopia? Thanks for your help.