New truths in ophthalmology / as developed by G. C. Savage.

  • G. C. Savage
Date:
1896
Catalogue details

Licence: Public Domain Mark

Credit: New truths in ophthalmology / as developed by G. C. Savage. Source: Wellcome Collection.

    35/288 page 23
    there is doubt as to the location of the axes. When one eye of a pair of oblique astigmatic eyes is covered, the strained ob- lique muscles do not always relax; and when this is the case, the cylinder given does not relieve the strain, however sharp it may make the vision. In some cases, the obliques do relax one eye being covered, and the cylinders are readily so placed as to reUeve all strain. In these two conditions the answers of the patients throw no doubt on the question of location of the axes of the cyHnders. There are other cases, and they are numerous, in which there is alternating contraction and relaxation of the obhques, the one eye being covered while the other is under observation. At one moment the patient declares that he sees best with the cylindrical axis at one point, and at the next moment he selects a point 5° removed. This is kept up until no conclusion can be reached, unless the operator has knowledge of the nature of oblique astig- matism. It is in such cases as these that Dr. Steele's rule may be safely followed; and that, too, without having to stop to determine whether the superior or inferior obliques are the strained pair.
    digitised image 1
    digitised image 2
    digitised image 3