On squinting, paralytic affections of the eye, and certain forms of impaired vision / by Carsten Holthouse.

  • Holthouse, C. (Carsten), 1810-1901.
Date:
1897
Catalogue details

Licence: Public Domain Mark

Credit: On squinting, paralytic affections of the eye, and certain forms of impaired vision / by Carsten Holthouse. 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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    On regarding objects in front of him^ while unobserved, one eye is always inverted, though not always the same eye, as he uses both indif- ferently, the vision of each being perfect; but if conscious that he is observed, he can prevent the inversion of either eye singly, and maintain them both very nearly parallel, that is to say, the convergence is so slight as to be almost unob- servable, and affects the two eyes equally. On looking sideways, one eye is too much inverted, and the other too little everted. Notwith- standing this want of parallelism, he positively declares that he sees an object, such as the finger held up to the side of him, with both eyes at a time; and sees it single, and this is the case whether the object be held to his right or left side. He never, under any circumstances, sees double. The power of everting both eyes is somewhat imperfect, he being unable to ap- proximate the cornea nearer than two lines of the outer canthus. This case throws much light on certain dis- puted points concerning binocular vision. It is well known that for single vision with both eyes, it is generally necessary that the image of an