Eye strain, also known as asthenopia, is a common condition that occurs when the eyes become tired and overworked. There are several synonyms for eye strain that describe the symptoms. Vision fatigue refers to the tiredness and discomfort that comes from using the eyes for extended periods. Eye fatigue and ocular fatigue are other phrases that describe the same condition. Digital eye strain, or computer vision syndrome, is a type of eye strain caused by extended computer use. Finally, eye fatigue syndrome and visual fatigue are additional synonyms for this condition commonly experienced by those who overuse or overexert their eyes.