I can find in text-books no systematization, no explicit statements, not even any distinct recognition of a series of clinical facts illustrated somewhat frequently in office practice, and still more frequently in hospital and dispensary work.
In thinking over my cases I have been surprised that so many have had eyestrain from causes beyond eradication or neutralization. The conditions being as they were, it was impossible to stop symptoms that were evidently due to what we call eyestrain. The causes simply could not be reached. We have looked at these conditions from every other standpoint except that of eyestrain, while it was precisely the eyestrain that mostly concerned the patient. Let us take this point of view:
Eyestrain1 may be defined as the local reflex, or general results of ocular effort caused by congenital or acquired defects or weaknesses of the optical or sensation-making mechanisms of the eyes, by
GOULD GM. INCURABLE EYESTRAIN.. JAMA. 1906;XLVII(10):734-739. doi:10.1001/jama.1906.25210100006002a