61 
Dr Gillies on a peculiar modification of Vision, 
ticipated in by every object within the range of my vision. 
Thus, I have observed a row of lamps of about three quarters of 
a mile in length, to bear the same proportional relation to my 
eyes as during my natural vision ; while, on the other hand, 
when seated in an apartment, and under the influence of this 
affection, had I trusted solely to my sensations of vision for in- 
formation, I should have been induced to think, that objects 
which I knew I could touch with my hand without rising from 
my seat, were removed several feet farther from me, and alto- 
gether beyond the reach of my fingers if I extended my arm. 
During the latter part of the Slst December 1816, when 
this affection seemed to have reached its greatest degree of in- 
tensity, on which occasion it continued with scarcely any inter- 
mission upwards of eight hours, these sensations were experien- 
ced in every variety of degree, from the slightest to the most in- 
tense form which I had ever experienced, and these often vary- 
ing and alternating with each other. 
Being very desirous to determine whether, during the con- 
tinuance of this affection, the apparent diminution in the 
magnitude and increase in the distance of surrounding ob- 
jects, bore the same relative proportion to each other which 
they did during my natural vision, I endeavoured to make 
some observations on this point ; but from the want of any 
good rule by which to estimate, and the fallacy to which all 
observations, resting solely on individual sensation, are liable, 
these have been very unsatisfactory, and I cannot speak with 
any certainty on the subject ; yet there is an impression on my 
mind, that they were exactly proportioned to each other. 
In general, I remarked that the distinctness of surrounding 
objects did not seem to be impaired in a greater degree, than if 
they had been actually removed to the same distance at which 
they appeared to be. 
I have never been able to assign any probable cause for the 
occurrence of this affection of my vision ; but it may be worthy 
of remark, that it never came on while I was engaged in read- 
ing or writing, or in any other occupation which required steady, 
continued, or minute attention, but most commonly attacked me 
when I was in company, or while engaged in conversation with 
any one, and when my eyes were employed viewing surround- 
