There is no one symptom so frequently complained of to the general practitioner as that of headache. It is the burden of suffering of civilized peoples. It is heard in connection with almost every case of impaired health, functional or organic.
The etiology of it we, as physicians, should most persistently endeavor to determine in each case. The late Dr. E. C. Seguin said: "The thorough study of a case of headache is one of the most difficult problems of medicine," and Alfred L. Loomis designated it as a "symptom of exceedingly difficult interpretation."
The reflex headaches or neuralgias due to essential eye-strain comprise the greater percentage of all cases met with. I have the records of over 1,280 eye examinations that justifies me in stating 90 per cent. of all those complaining of this distressing malady had ocular defects.
These examinations—most of which were made as part of routine
TOMS SWS. THE RELATION OF EYE-STRAIN TO CHRONIC HEADACHES.. JAMA. 1907;XLVIII(12):1009-1010. doi:10.1001/jama.1907.25220380025001e