Asthenopia

(as-then-o' -pe-ah). Weakne , speedy fatigue of the ocular muscles or visual powers, due to errors of refraction, insufficiency, over-use, anemia, etc. A., Accommodative, due to hyperopia, astigmatism, or a combination of the two, producing strain of the ciliary muscle. A., Muscular, due to weakne , incoordination (hetero pho ria), or strain of the external ocular muscles. A., Retinal, or Nervous, a rare variety, caused by retinal hyperesthesia, anesthesia, or other abnormality, or by general nervous affections.