- Subjective symptoms of ocular fatigue, discomfort, lacrimation, and headaches arising from the use of eyes.
- Weakness or tiring of eyes accompanied by pain, headache, and dimness of vision.
- Accommodative asthenopia: strain of ciliary muscle and refractive error.
- Photogenous asthenopia: excessive or improper illumination.
- Muscular asthenopia: due to imbalance of the extraocular muscles
- Nervous asthenopia: due to functional or organize nervous disease
- Pain in and around eyes
- Headache, usually aggravated by use of eyes for closework
- Reflex symptoms as nausea, twitching of facial muscles, migraine.
- American Academy of Ophthalmology. Pediatric Ophthalmology/Strabismus: Asthenopia Practicing Ophthalmologists Learning System, 2017 - 2019 San Francisco: American Academy of Ophthalmology, 2017.
- Taber's Cylocpeic Medical Dictionary
- Stedman's Medical Dictionary