466 
POPULAE SCIENCE EEVIEW. 
class of glaucomatous disease of the eye — disease characterized 
by loss of vision^ sometimes slow and sometimes rapid^ but 
always characterized by definite ophthalmoscopic signs : 
cupping of the disc, pulsation, fulness of the veins, and it 
may be, more or less haziness of the transparent media, 
ophthalmoscopy has rendered a most brilliant and inesti- 
mable service. Prior to the introduction of the use of this 
instrument the disease was of an unknown pathology; its 
results were fatal to vision, but there were no means of 
diagnosing the conditions attending the earlier stages, and 
blindness followed almost certainly and inevitably. The 
investigation of the disease has brought us a remedy in the 
excision of a portion of the iris — a practice introduced by 
Yon Grafe, of Berlin, and of which the success is in suitable 
cases most gratifying. 
Another series of examples may be chosen to illustrate the 
application of ophthalmoscopy. I avoid giving details here, 
but it is perhaps right to say that these are not fanciful 
sketches, but notices of cases in my experience and taken 
from my note-books of practice. Two persons are asking for 
advice as to the management of their eyes for short-sightedness. 
Are both to receive the same advice ? The ophthalmoscope alone 
can furnish positive data. With this we may discover a staphy- 
lomatous condition of the back of the eye, a bright excentric 
margin around the optic disc and edged with black pigment. 
Examining it closely, we may find that this pigmented edge 
gives evidence of progressive inflammation at the back of the 
eye, and extending to continuous and increasing atrophy 
and retrocession of the coats of the eye. This person is in 
danger of becoming rapidly made short-sighted or of losing 
sight altogether. We must prohibit the use of concave glasses 
for a certain length of time, and must adopt active and 
effectual measures for subduing the atrophic inflammation. In 
the other patient the ophthalmoscope may show us but little 
stretching or waste, and that not progressive, and will enable 
us then to calm his fears, to prescribe appropriate glasses, and to 
dismiss him to his occupation with ease of mind and safety. 
So with sudden Joss of sight from intra-ocular heemorrhage, the 
ophthalmoscope gives us information which could never have 
been guessed at without it, and guides us, not only to the local 
knowledge, but to the constitutional information essential for 
cure. 
There are certain conditions of the eye which may warn 
any one that it is desirable that the condition of the vision 
ought to be investigated by the ophthalmoscope. Eapidly 
increasing short-sightedness is one of the most marked, and 
when this becomes associated with weakness of sight and loss 
