On the influence of artificial light in causing impaired vision, and on some methods of preventing, or lessening, its injurious action on the eye / by James Hunter.

Date:
1840
Catalogue details

Licence: Public Domain Mark

Credit: On the influence of artificial light in causing impaired vision, and on some methods of preventing, or lessening, its injurious action on the eye / by James Hunter. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

    23/104 (page 13)
    During this state of morbidly increased sensibi- lity to light, there is very often during the day time, a dull heavy feeling in the forehead, hardly amounting to pain, but causing the patient fre- quently to pass his hand across his brow ; and in reading or writing at night there is an unpleasant sensation of distention in the orbits, along with in- creased lachrymation, and frequent twittering or quivering of the eyelids. Another very constant symptom, at this period of the disease, is the ap- pearance of brilliant flashes of fire when the eyes are touched or rubbed, however gently, in the dark. In many cases these flashes are seen even without the eyes being touched; and they are very common on first lying down in bed, particularly after read- ing, writing, or sewing, for some hours previously by candle, or other artificial light. When these symp- toms have continued for a time varying from a few weeks to as many months, and sometimes not till after a year or more, they are followed by others, of a totally different, and much more alarming na- ture, indicative of diminished sensibility of the nerves of vision. Of these symptoms, the first no- ticed is the appearance of and rendered invisible during that time. This has been accom- plished by making the eyelids move with great rapidity, and by giving to the retina a power of retaining the impressions of light during the interval.