On the nature, and cure of strabismus : by operation / by J.A. Ratton.
- Ratton, James Alban, 1814-1865.
- Date:
- 1842
Licence: Public Domain Mark
Credit: On the nature, and cure of strabismus : by operation / by J.A. Ratton. 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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![parallelism consists in : and to understand which fully it was necessary that we should in the first instance have some little previous knowlege of the anatomy of the eye, as well as, a general idea of the principles of optics,f by which we provegeometrica]]y,how the rays of light are refracted through all the humours of the eye so as to form a distinct picture on the retina. + Let us in the first place then understand this subject: and then observe the relation it bears to the parallelism of the ej'es; rendered as it is more interesting at the pre- sent moment, in connection with the subject of squint- ing. 1 he Physiology of vision to be properly under- stood must be studied in its two-fold relaiion in con- nection with mathematics as well as with anatomy ioi to view it from either of these sciences singly, could tend but to a mischievous fallacy, the fallacy of induc- tion from false data—for as we perceive mere mathe- maticans have been impressed with the notion that the centre of the spherical surface of the retina, and the centre of the lesser spherical surface of the cornea, are ^le same. On the other hand anatomists have as- cribed too much to the lens, and too little to the cor- nea,—considering the former to be the chief medium of refraction in the eye, whereas they should more cor- rectly have ascribed the greater refracting power to the latter.—Hence they state that when the lens is lost, as after operation for cataract, the powers of the eye are greatly weakened; that is to a greater sitrlif1 C|*')SS r^aHelism ol the eyes ancl strange illusions of biglH-Dr Crichton, vol. t.p. 147. 6 ini!- -m 1° iTV1,113 —''CS vol‘ f- In 1',v,1'ch is also mentioned a case of squint- ing ami double vtMon occasioned by a blow. t 'I ilia was fiist shewn by Keppler in 1600.](https://iiif.wellcomecollection.org/image/b22336813_0129.jp2/full/800%2C/0/default.jpg)
