THE RELATION 0T EYE-STRAIN TO HEADACHE. 
BY EDVARD JACKSON, M.D., 
IF PHILADELPHIA. 
Reprinted from Transactions of the State Medical Society, 1886. 
Headache due to eye-strain is very common. There are few 
persons who have not felt it. With many it is merely incidental, 
and so far out of their ordinary experience as to be of no impor- 
tance. But with very many it is a cause of sufficient suffering and 
impairment of working power to demand serious attention. The 
constant tendency of business and amusement is to tax the eyes 
more heavily. Rough mechanical labor is more and more accom- 
plished by machinery; while that requiring accurate and constant 
adjustment is multiplied, to occupy the human brain working with 
eye and hand ; and leisure means, more and more generally, the ex- 
ception of sight from the general rest of faculties taxed by labor. 
To one who knows this and reflects upon it, it can be no matter of 
wonder that the balance between the capacity for seeing and the 
supposed need for seeing is so often lost. 
To pursue the subject from simple fact toward abstract generali- 
zation, I shall introduce a few cases; of interest, not because they 
are so rare, but because they are so common. 
Case 1.-W. S. D., set. twenty-five; lawyer, of fine physique. As 
a boy was subject to almost constant headache, and violent attacks of 
hemicrania occurring as often as once a week, which compelled the 
cessation of all exertion, mental and bodily, sleep giving relief. 
When in school, the attacks were apt to occur toward the close of the 
week, then came a day or two of comparative immunity, then, with 
school-work, increasing headache, culminating in another attack. 
The attack commenced with pain in the left frontal or occipital 
region, whence it spread over the whole left side of the head. In 
January, 1882, he was found to have compound hypermetropic 
astigmatism, the correcting lenses being 
R. + 2.5 s. O + 0.5 cy. axis 90°. 
L. + 5.25 s. O + 0.5 cy. axis 75°. 
He was ordered lenses correcting the astigmatism and most of 
the hypermetropia, and wore them, with entire freedom from head- 
1 2 
ache, until January of the present year, when the glasses were 
broken, and he neglected to have then repaired. He was now 
in excellent general health, and for s time suffered but little 
inconvenience from eye-work without glasses. "But \by and by 
there was some irritation of the eyes, particularly the left, after 
using them; then a little headache, and,finally, in March, a well- 
marked attack of the old enemy, " sick-ueadache." He then re- 
ported to me, resumed the use of glasses, and the headache disap- 
peared. 
This case is one of a considerable cl as, where, in persons of 
good muscular development and general health, supplied with 
abundant nourishment and working under favorable conditions, an 
error of refraction entails eye-strain sufficient to alone set up serious 
headache. But the next case belongs to a still larger class. 
Case 2.-Mrs. C. T., set. thirty-three; rather thin, and decidedly 
ansemic; did not sleep well, with poor appetite, endometritis and leu- 
corrhoea; consulted me in April, 1883, on account of headache. This 
was rarely entirely absent, but there were attacks in which the pain, 
commencing in the frontal region, spread over the entire head, be- 
came terribly severe, causing complete prostration, and compelled 
rest in bed for one, two or three days. These attacks had for some 
months occurred as often as once a week. Menstruation was always 
attended with one, and this had been the case for years. There was 
also a fixed pain in the occiput and back of the neck, and some 
pain in the lower part of the back. She had been under the care 
of an intelligent and very careful physician, who had faithfully 
advised the usual remedies for such disorders. He reported that 
local treatment of the cervix uteri, with fuming nitric acid, a period 
of complete rest away from home, a course of iron, and a prescription 
containing phosphorus and strychnia, had each seemed to cause some 
improvement in her condition ; but the improvement was not great 
enough or lasting enough to warrant the continuance of the remedy, 
or to be at all satisfactory to either patient or physician, and the 
latter had advised a trial of glasses as about the only thing necessary 
to complete the circle of therapeutic experiment. 
Her history was that the headaches came on after any exertion, 
not especially after eye-work, but that there was the clear connec- 
tion with the menstrual epoch. The ophthalmoscope revealed a 
low degree of hypermetropia. Her eyes were placed under the 
influence of duboisia, giving rest to the mechanism of accommoda- 3 
tion. In ten days she returned to say that within a few hours after 
commencing the use of duboisia headache had disappeared, and 
from that time she had been entirely free from it. She was now 
given her full correction, 
R. + 1.25 s. O + 0.5 cy. axis 145°, 
L. -f- 1.25 spherical, 
to wear constantly, and directed to continue the use of the duboisia 
for a month. During this time menstruation occurred, but she re- 
mained free from headache, and the pain in the occiput and back 
of the neck entirely disappeared. 
After ceasing the use of duboisia, she again had occasional head- 
ache, but nothing like her old attacks; although there usually is 
still some headache at the menstrual period. She continues thus 
using her correcting lenses and living in comparative comfort. But 
when I saw her again in April of this year, she alluded to the 
time, when her eyes were under the influence of the mydriatic, as 
the longest period of complete immunity from headache that she 
ever had. It should be mentioned, that during that time she was 
at home, leading her ordinary life, except as eye-work was suspended, 
and no other remedial measures were resorted to. 
Note, especially, with reference to this case, the absolute freedom 
from headache coincident with the complete suspension of accom- 
modative effort; the return of slight liability to headache with the 
return to accommodative effort under more favorable conditions; 
and that the occurrence of severe attacks seemed entirely indepen- 
dent of any use of the eyes. 
In both the foregoing cases excessive accommodative effort was 
necessitated by the presence of hypermetropic astigmatism, but head- 
ache may arise in the same way where eye is perfectly emmetropic. 
Case 3.-W. G., a young man of nineteen, of good general 
health, but a hard student; during the winter of 1884 had increas- 
ing headache and failure of accommodative power and endurance. 
By the beginning of February these had almost rendered study 
impossible. Under homatropin the refraction of both eyes was 
proven practically emmetropic (less than 0.25D hypermetropic astig- 
matism in either). I gave him minute instructions as to how to 
use his eyes for study with the least possible demand upon accom- 
modative power, and ordered, for near work, for each eye -J- l.D 
spherical with a 2° prism base toward the nose; that the accommo- 4 
dation might be assisted without interfering with the relation be- 
tween accommodation and convergence. The use of the homatropin 
necessitated two days' suspension of school-work. After that he 
went right on, doing the work under which he had just broken 
down. Improvement commenced at once and progressed steadily 
until, a month later, he was entirely free from headache or asthenopic 
symptoms. He continued his work without other inconvenience 
up to the end of the school-year, and then, with lessened demand 
on the power of accommodation, was able to throw aside the glasses 
altogether. 
But eye-work may cause headache by strain other than that upon 
the power of accommodation. As a symptom of insufficiency of 
the internal recti in myopia it is quite generally appreciated, but it 
is not always remembered that the same insufficiency may arise from 
excessive near work in those whose refraction is emmetropic or 
hypermetropic. 
Case 4.-D. L. C., set. twenty-three, student, came to me in Feb- 
ruary last for frontal and occipital headache, increasing greatly with 
any near work, and rendering its continuance impossible after from 
ten minutes to half an hour. Refraction emmetropic in both eyes. 
For both near and distant vision there was an insufficiency of the 
internal recti muscles, leading to an outward deviation of the eyes 
of about 8°, when vertical diplopia was produced. He was given 
a prism of 2° base to the median line for constant use. A month 
later he reported himself entirely free from headaches, and has con- 
tinued so except once, when he tried to go without his glasses. 
I will not pass this case, however, without remarking that I do 
not expect the relief to be permanent. The power of all his ocular 
muscles is markedly deficient, and although the prisms have secured 
a temporary balance between capacity for effort and effort required, 
this balance is very liable to be destroyed. The relief of muscular 
insufficiency by prisms is very different from the correction of ame- 
tropia by lenses. 
Dr. Henry D. Noyes has called attention to insufficiency of the 
external recti muscles. Of this condition headache has been a very 
prominent symptom in the few cases I have recognized. For some 
years I have also, as a matter of routine, tested the balance of the 
superior and inferior recti muscles, or, more properly, the balance of 
all muscles tending to turn the eye up and down. The following 
case of deficiency in this respect is of interest here. 5 
Case 5.-M. C. McF., set. fifty-three, farmer, has been subject to 
headaches "all his life." These were most severe just back of the 
bridge of the nose and in the occiput. Were worse after using the 
eyes for near or distant vision, as after reading, or being on the 
road or in town. About once a week he had a specially severe 
attack, which would frequently confine him to bed for the whole 
day. He has tried many things for the relief of these headaches, 
but without benefit. He was emmetropic with a near point of six- 
teen inches, and full vision for each eye. There was a very slight 
insufficiency of the internal recti for objects within twelve inches of 
the eye. To cause vertical diplopia it required a prism of 2° to 3°, 
base up, before the right eye, and one of at least 4° before the left 
eye. 
This tendency to vertical deviation was constant, whether he 
looked up or down, to the right or left, at near or distant objects. 
He always overcame it, so that diplopia did not occur; but the 
effort to overcome it seemed to be the only chance for eye-strain, 
and the history pointed clearly to the increase of headache by the 
use of the eyes. I therefore ordered for distant vision 
Right, plane glass ; 
Left, prism 1° base up ; 
and for near work the proper spherical lenses, so decentred as to 
give the same prismatic effect. These were ordered last June. Two 
months later he told me he had not had a headache since he got the 
glasses; and a month after that his wife (bringing a daughter as a 
patient) said her husband never had such freedom from headache 
in the thirty years she had known him. 
The cases now introduced will serve to illustrate the facts with 
reference to these headaches; that they do not depend upon a cer- 
tain defect in refraction, nor upon the strain of any particulai- 
muscle, but that they arise from requiring of the muscles accessory 
to vision, or of the nerve centres and tracts connected with them, 
more than these portions of the muscular or nervous system are 
capable of doing. Subjection to such a requirement is the essence 
of eye-strain. 
Of the clinical characters of these headaches, I need only say 
that they are identical with those of all other classes of headaches, 
and, therefore, do not aid in the diagnosis of the cause. Such 
diagnosis may rest sometimes on the sequence of strain and each, 6 
but at others is only to be determined by the therapeutic test, the 
removal of all possible strain. 
In the whole domain of medicine there is no subject that has 
been more completely given over to unprofitable theorizing than 
the pathology of headache. " Cerebral anaemia," " cerebral hyper- 
aemia," " vasomotor spasm," " vasomotor palsy," " blood poison- 
ing," " reflex irritation " and " nerve storm " have struggled for 
possession of the field. And in the mind of the practitioner success 
generally rested with the first theory propounded, or the one set 
forth in the most specious and best-rounded sentences. Still, scien- 
tific advance is mostly made along the lines of some working hypoth- 
esis ; and I wish briefly to outline the one I hold with reference to 
these headaches of eye-strain, believing it will prove helpful to a 
better understanding of them and fruitful in practical results. 
Pain I take as a consciousness of impaired nutrition in some por- 
tion of the nervous system. It is not a special sense; it is not an 
exaltation, or, in any ordinary sense, an alteration of smell, sight- 
hearing, taste or touch. It may coexist with these, but is no part 
of them. The force and significance of this view will appear to one 
who reads with careful consideration the works of Anstie, particu- 
larly his " Stimulants and Narcotics," and " Neuralgia and Its 
Counterfeits." 
A second point cannot be better stated than in these words of 
Hilton (" Rest and Pain "). " If a patient complains of pain on 
the surface of the body, it must be expressed by the nerve which 
resides there ; there is no other structure that can express it. Some- 
where in the course of its distribution between its peripheral term- 
ination and its central origin, the precise cause of the pain expressed 
on the surface must be situated." 
Now, headache is pain referred to the distribution of the fifth 
cranial and second cervical nerves. Eye-strain is excessive exertion 
of the ocular muscles and the efferent nerve paths that lead to 
them. Is it any forced or unwarrantable supposition that, if the 
use of one nerve path disorders the nutrition of another, such dis- 
order must occur where such paths are closely contiguous or 
actually run together? Now, the fifth nerve is distributed to the 
portions supplied by the motor-nerves of the ocular muscles. But 
the great occipital nerve has no such connection. There is another 
fact opposed to the supposition that the harm done the fifth nerve 
is done at its peripheral terminations, viz., that when headache 7 
occurs you are not specially apt to have any local lesion of the eye 
or its appendages. Given a certain amount of eye-strain, and you 
may have headache or you may have local irritation or inflamma- 
tion ; occasionally they coexist, but usually they do not. The oc- 
currence of one, probably by checking the strain, tends to prevent 
the occurrence of the other. The next point at which these motor 
and sensory tracts come in contact is in the medulla. The fifth, by 
its extensive connections with the gray matter of the medulla, comes 
closely in contact with the nuclei of all the cranial motor-nerves. At 
the same point the second cervical comes in relation with them. 
Here may be located the essential morbid condition of eye-head- 
aches. Nor would headaches arising from other sources demand 
the different location of their essential lesion. Such essential morbid 
condition is a vice of nutrition, unrelated to any known appearances, 
either gross or microscopic, but related to certain facts of physiology 
and pathology. The nutrition of this portion of the nervous sys- 
tem, of course, depends on both local and general influences; among 
the former, its vascular supply and the demands on it in the way of 
functional performance; of the latter, the condition of the blood 
throughout the body, and the nervous influences bearing on it from 
all parts of the nervous system. 
Its nutrition would be improved by functional rest, or a better 
vascular tone, or by any influence enriching the blood or removing 
irritation or strain from distant organs. An eye-headache is not 
only aggravated by eye-work; it is aggravated, or even set up, by 
the return of the menstrual epoch, by hunger, by antenna, by ex- 
haustion of body or mind, or by the lowered general character of 
nutrition after exhausting illness. And, conversely, it is not bene- 
fited merely by lenses and prisms, atropia or the dark room; but 
by sleep, food, tonics, wholesome living-all influences that improve 
the nutritive processes throughout the body. But the converse is 
also true, and I think, on the present occasion, needs to be most 
insisted on. That because you find a headache is benefited by a 
hearty meal, or a restricted diet, or a brisk purge, or a rest from busi- 
ness, or a course of iron and strychnia, or the wearing of a pessary, 
you are not warranted in supposing that eye-strain has nothing to do 
with that headache. If one of the measures above mentioned bring 
about complete recovery, well and good; nice points of pathology may 
well be waived. But if, of these remedies, some, or all, presently 
lose their control, and the headache returns to be a plague and in- 8 
cubus, justice will not have been done the patient until the possi- 
bility of eye-strain is excluded. Eye-strain, like many other dis- 
orders, is of double parentage-remove one parent and propaga- 
tion ceases. If you cannot bring nutrition up to where the nerve- 
tracts will readily do all that has been required of them, it may be 
possible to reduce the effort required to within the capacity of these 
nerve-tracts. It is, however, entirely conceivable that a morbid 
condition may become so thoroughly engrafted upon the system 
that the simple removal of its original cause is followed, but dis- 
tantly, or not at all, by recovery, This is sometimes the case with 
the headaches under consideration, especially well-marked migraine, 
which is certainly often, and perhaps always, due in part to eye- 
strain. 
215 South Seventeenth Street.