XVIe Congrès international de médecine, Budapest, août-septembre 1909 sec. 9 fase 21910 |
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Page xlvii - A ray of light impinging on the retina liberates the visual purple from the rods and a photograph is formed. The rods are concerned only with the formation and distribution of the visual purple, not with the conveyance of light impulses to the brain. The...
Page 386 - The character of the stimulus and impulse differs according to the wave-length of the light causing it. In the impulse itself we have the physiological basis of the sensation of light, and in the quality of the impulse the physiological basis of the sensation of colour.
Page 386 - ... and a visual impulse is set up which is conveyed through the optic nerve fibres to the brain. The character of the stimulus differs according to the wave length of the light causing it.
Page 386 - The decomposition of the visual purple by light chemically stimulates the ends of the cones (very probably through the electricity which is produced), and a visual impulse is set up, which is conveyed through the optic nerve fibres to the brain.
Page 269 - II or, in favorable cases, or cases which have been treated, into trachoma III or IV. Trachoma II is the stage in which granulations are numerous and large, or in which a papillary hypertrophy is present. It may be divided in the above sense into trachoma Ila and trachoma lib. Trachoma Ila. Gelatinous granules are present all over the tarsi and in the upper fornix. In some cases the individual granulations can no longer be distinguished, and they fuse into tumor-like masses or merge into a general...
Page 395 - The trichremic see three main colours in the spectrum — red, green, and violet. They •usually describe the spectrum as consisting of red, red-green, green, green-violet, and violet. They do not see yellow and blue as distinct colours, and are therefore in continual difficulty over them. There are very few of the tests in general use which can detect them, especially if names be not used. They will usually pass a matching test with ease. An examination with the spectrum shows that their colour-perception...
Page 386 - Light falling upon the retina liberates the visual purple from the rods, and it is diffused into the fovea and other parts of the rod and cone layer of the retina. The decomposition of the visual purple by light chemically stimulates the ends of the cones...
Page 378 - A propos de celle même observation, communiquée à la Société d'ophtalmologie de Paris, A. Terson rappela un cas de fistule lacrymale chez une jeune fille, où la syphilis héréditaire avait, dès la première enfance, détruit la cloison des fosses nasales, le cornet inférieur, et obstrué définitivement la partie inférieure du canal naso-lacrymal d'un côté. Avant de parler de ces dacryocystites franchement consécutives à dos lésions de voisinage, signalons celles qui semblent, si toutefois...
Page 269 - Trachoma III. In. this stage cicatrisation has definitely begun, and is more or less advanced. Islands of inflamed conjunctiva or of trachomatous granules are seen to be surrounded by a network of fine lines of connective tissue. It is in this stage that necrosis often results from the pressure of the shrinking connective tissue (post-trachomatous degeneration). The necrotic tissue may become calcareous. The cicatrisation which is typisal of this stage is generally supposed to XVI
Page 376 - ... la Chapelle et dans la clientèle privée. Il s'agit de ceci : Si l'on promène la pulpe de l'index, à partir de l'arête du nez et un peu plus bas que la racine, en descendant de côté, à droite ou à gauche, pour suivre à la palpation le bord...