The directions of the apparent vertical and horizontal meridians of the retina and their modification from physiological and pathological causes : with a description of the clinoscope / by George T. Stevens.

  • Stevens, George T. (George Thomas), 1832-1921.
Date:
[1897]
Catalogue details

Licence: Public Domain Mark

Credit: The directions of the apparent vertical and horizontal meridians of the retina and their modification from physiological and pathological causes : with a description of the clinoscope / by George T. Stevens. 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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    converging the eyes to a point one half the distance of the point of regard. The Clinoscope.—For the accomplishment of all these con- ditions I have devised the instrument which I am about to describe and which I have called the Clinoscope. This instru- ment appears to meet the demands not only of the physio- logical investigator in his theoretical researches in respect to the horopter, but supplies a means for practical examina- tions of the retinal meridians, the necessity for which has not been hitherto felt and for which no provision has been made. The instrument appears to me to be essential to all the investigations to which I have referred, and by its use we shall, I doubt not, be able to establish such correct data as to enable us to harmonize the conflicting views of the in- quirers who have left the subject of the horopter to be regarded, not as a subject of practical importance, which it is, but as an individual peculiarity varying with the ex- perimenter, and therefore of little, if any, physiological interest. By correct methods of examinations into the phenomena the subject may be placed, where Helmholtz believed it should be, on a firm basis of scientific accuracy and uniformity. Fig. r. The instrument (Fig. i) consists of two hollow cylinders, each about 2.50 centimetres in diameter and one half metre in length. The tubes are mounted on a brass platform, which holds them firmly in the same horizontal plane at a distance