Asthenopia

Asthenopia 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.

Causes
Sometimes, asthenopia can be due to specific visual problems, such as uncorrected refraction errors or binocular vision problems like accommodative insufficiency or heterophoria.