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

  • Savage, G. C. (Giles Christopher), 1854-1930.
Date:
1896
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Licence: Public Domain Mark

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

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

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    muscles must always keep the naturally vertical meridians parallel, I readily fell into the error of teaching that the action of the obliques caused by oblique astigmatism was harmonious non-symmetric. I at that time conceived the purpose of the rotation to be to bring the meridian of best curvature to, or as far as possible toward, the vertical or horizontal position, a work in which the obliques were often aided by a leaning of the head toward the shoulder. I then thought that vertical (and horizontal) astigmatism gave least trouble, because of the mere fact of position; but now I can understand why oblique astigmatism, with meridians of great- est curvature parallel, will give as little trouble, for in each of these conditions any object will throw similar images on corresponding retinal parts. For the reason that the ob- liques do not have to perform their complicated function in these forms of astigmatism, their correction is never attended by metamorphopsia or other annoyance. I try always to have a reason for the faith that is within me, and any change of faith or teaching on my part must be based on reason. My reason -for abandoning the teach- ing of harmonious non-symmetric action of the obliques in oblique astigmatism, and in its place teaching that these muscles must act symmetrically, is that the refraction of such eyes causes the formation of dissimilar images on non-cor- responding parts of the retinas. This thought of oblique images in oblique astigmatism occurred to me one night