The relief of headaches by the correction of errors of refraction / by Duncan Matheson Mackay.

  • Mackay, Duncan Matheson.
Date:
1909
Catalogue details

Licence: In copyright

Credit: The relief of headaches by the correction of errors of refraction / by Duncan Matheson Mackay. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    And so he resigns himself to the inevitable, and, recognising that his muscular efforts are fruitless, refuses to make them. He, therefore, has no headache, but he has no clear vision. Another class of ametropes who do not suffer from headache are those who do not use their eyes for anything that requires exact observation ; this is probably the reason that it is amongst the indoor-workers—dressmakers and clerks, students and teachers,—that we find the headaches, rather than amongst the outdoor-workers—farm labourers, carters, and domestic servants who do not have sewing as part of their duties. In this connection, too, one understands why the Ame- rican insists upon the correction of errors of refraction even more than the Englishman, and why the Englishman insists more than the Continental.11 For in the States, life seems to be more strenuous than in England, while the Continen- tal, though his hours of work are long, works much more leisurely. And then one must remember that other conditions have to be considered—conditions, mainly, of the general health, and of excessive nervous sensibility. The ciliary muscle, like any other muscle, is affected by lowered vitality, which comes with years. And, therefore, whereas a child can keep up a contrac- tion of the ciliary muscle for a long time without discomfort, an older person is rendered uncomfortable by a much shorter period of activity. And as the muscular system is most vigorous at the beginning of the day, one can understand why the first complaints are usually made at the end of the day,, for then the ciliary muscle has been used for several hours. Similarly, convalescence from a long illness may be the occa- sion of a person’s first noticing dimness of vision or discomfort after the use of the eyes. This, again, explains why holidays may remove the headache, not only because holidays usually mean a rest from close work, but also because they restore the muscular vigour by means of an open-air life. And in like manner, refraction headaches may be removed by tonic medicines in some cases. The amount of the error, of course, affects the amount of contraction that needs to be exerted :—i or 2 D may be overcome comfortably, while the attempt to overcome 4 or 5 D quickly provokes pain. And no one habitually uses the whole of the contractile power of the muscle ; 50 per cent-