Eye strain / asthenopia are terms which refer to a group of symptoms related to the experience of discomfort felt when viewing something, often for prolonged periods. Although often painful, eye strain does not lead to permanent damage to the eye.The symptoms of eye strain are many and varied and may include;Headachesblurred visionLight sensitivityred, watery eyespainful or sore eyesdry eyestired eyesback and neck achesmuscle spasmsMost, if not all, symptoms of eye strain are easily remedied, however if these symptoms become persistent or worsen it is advisable that you visit your optician as soon as possible.