Asthenopia (aesthenopia) or eye strain is an ophthalmological condition that manifests itself through nonspecific symptoms such as fatigue, red eyes, eye strain, 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.

When concentrating on a visually intense task, such as continuously focusing on a book or computer monitor, the inner eye muscles may tighten, which can cause the eyes to get irritated, dry, and uncomfortable. Giving the eyes a chance to focus on a distant object at least once an hour usually alleviates the problem. Small font sizes exacerbate the strain if they cause unconscious squinting or straining to focus.^{[citation needed]}

I just discovered what has been keeping me from reading books longer than i used to. Asthenopia. Kanikanina ko lang sineryoso ang problematic eyesight kong ito. For example: I look at the monitor right? And then when i immediately look down on the keyboard, para bang nagkakaron ako ng double vision of some sort, where i see all the letters scrambled up as if one is overlapping the other. 3D vision, but not quite yet. It's really weird. I didn't even know there's such an eyecondition as this until i looked up Astigmatism @ Google and resulted in another wikipedia wonder which is this. My eyes are having a hard time focusing which resulted to these weird images. Kahit ngayon habang nagtatype ako sa monitor, i can see it happen again. Haha. Dang, i need to change my font sizes. As well as lessen my time with the computer from now on. But that also means i have to lessen my time reading!! Argh. O well, ayoko namang magkaganto ulit ako pagdating ng september. Kaya kelangan. Ganto kasi nangyari saken last sem kaya medyo hindi ako nakakapagbasa ng matagalan. Thus, less time studying. Weird noh?