[Reprinted from The Medical News, March 16, 1895.] 
PRELIMINARY NOTE UPON A FEW OF THE 
CHANGES FOUND IN THE FIELDS OF VISION 
WHILE THE EYES ARE PLACED AT 
RIGHT ANGLES TO THEIR 
ORDINARY POS! TION. 
By CHARLES A. OLIVER, AM., M.D., 
ATTENDING SURGEON TO THE WILLS EYE HOSPITAL; OPHTHALMIC 
SURGEON TO THE PHILADELPHIA AND PHEBliYTERI AN 
UIW**** 
In the fall of 1893, during a conversation with 
Dr. S. Weir Mitchell, of this city, he spoke to me 
of the advisability of conducting a series of scientific 
experiments in order to determine why it is that a 
more vivid color-impression of a distant landscape 
can be obtained when the head is bent down into a 
horizontal position. To perform these properly Dr. 
Mitchell suggested that a study of the relative values 
of both form and color-fields whilst the head is held 
in the ordinary upright position and whilst it is 
lowered into as near a horizontal one as possible, 
might be of use in determining the reason. 
These experiments, which I performed with the 
aid of a number of assistants and friends, will be 
fully explained in a paper that, although finished 
some several months ago, is being reserved for later 
publication. 
After duly considering the differences of color- 2 
values when reflected through the various meridians 
of the dioptric media and the increase of physiologic 
power from greater blood-supply to the organ when 
the head is held in the lowered position, the con- 
clusions reached in this paper, after some two hun- 
dred or more experiments, show definitely that such 
a change in the position of the eye practically 
brings the most sentient portion of the retinal sheet 
into a situation that allows it to receive impressions 
from a part of a distant view that ordinarily im- 
pinge upon a lower grade of material, which gives 
a less vivid and a less detailed visual picture.