Lectures on diseases of the eye / by N.C. Macnamara. Part I., Referring principally to those affections requiring the aid of the ophthalmoscope for their diagnosis.

  • Macnamara, Nottidge Charles, 1832-1918.
Date:
1866
Catalogue details

Licence: Public Domain Mark

Credit: Lectures on diseases of the eye / by N.C. Macnamara. Part I., Referring principally to those affections requiring the aid of the ophthalmoscope for their diagnosis. 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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    sistant should stand behind the observer holding a large white card, or some such conspicuous object, in his hand, upon which the patient is directed to fix the eye under examination. For the right eye, the card must be held over the observer's right shoulder, and for the left one, over the left. By this means the patient's eye is inclined slightly inwards, and the rays of light from the ophthalmoscope will fall directly upon the optic disc. In the case of a blind man, no arrangement of this kind can be made, and it fre- quently involves a great trial of patience and in- genuity, to get such a person to hold his eye steady, even for a few seconds, in the direction required. It is abso- lutely necessary however, under any circumstances, that the patient should keep his head erect, and directly opposite the observer's; unless this be in- sisted on, it is impossible to make a satisfactory exa- mination. In using the ophthalmoscope, the sight- hole of the instrument should be applied to whichever of the observer's eyes is most convenient to himself, its rim being made to rest against his eyebrow, and as he turns his head, the instrument will move with it. The lens in front of the patient's eye should be held between the thumb and fore-finger of the other hand, the index and middle finger resting against his forehead, which thus acts as a fixed point, enabling the observer to approximate or withdraw the lens, so as to bring the retina into focus with the greatest precision, and also to follow the movements of the eye under examination. The beginner may be troubled by the reflection of c 2