1864.]| Nonnetnx on the History and Uses of the Ophthalmoscope. 423 
neglect of which is of such fearful consequence to the sufferer. 
Now it is precisely this serious class of most obscure changes in the 
deeper, more delicate, more important, and most hidden recesses of 
the eyeball, that the ophthalmoscope is destined to light up and reveal 
with a clearness which will remove most, if not all, of the obscurity 
which has hitherto concealed them. During the last century no branch 
of medicine has made greater strides towards attaining scientific 
precision than has ophthalmic surgery, which has been rescued 
from the hands of the impudent charlatan and the wandering mounte- 
bank, to become in many respects the most advanced branch of 
practical medicine ; yet it must be admitted by everyone, who from 
attention to the matter is qualified to give an opinion on the subject, 
that it is in precisely these more important diseases of the eyeball, (in 
which it is of the utmost consequence to attain an early knowledge of 
the kind of change which is going on, and the particular structure in 
which it is taking place,) that hitherto there has been the greatest 
difficulty in so doing. The outer structures of the eye are within 
reach and amenable to the examination of everyone ; not so the inner. 
In the earlier stages of disease in these, when examined by the ordinary 
method, there are often no objective symptoms, while the subjective 
phenomena are so obscure and confused, as to be not unfrequently of 
little certainty or value. Hereafter, the ophthalmoscope promises to, 
nay, certainly will, remove much of the obscurity, and it cannot fail 
to render the diagnosis of these terrible and insidious changes in the 
deeper seated tissues of the eye almost as much within the sight of 
an expert observer as are those in the most superficial parts; and by 
thus enabling the competent oculist to detect the earliest indications 
of change (which hitherto has been too frequently beyond his power 
of observation), it will allow him, by timely treatment, to prevent alter- 
ations, which would otherwise, if unobserved, progress until all chance 
for good being effected has passed away, and hopeless blindness has 
become the inevitable lot of the unhappy patient. In many of these 
changes, if far advanced, there is no cure; in them prevention is not 
only better than cure, but it is emphatically the only cure. 
Though it is barely a dozen years since the ophthalmoscope began, 
in the hands of Briicke and Helmholtz, to assume a form of practical 
application, the idea of such an apparatus, or rather the principle 
upon which such a method of examining the eye,depends, was first 
clearly indicated by one of our own countrymen, Mr. Cumming; 
who, in an admirable paper, published in the ‘Medico-chirurgical 
Transactions for 1846, clearly pointed out the importance of 
observing the light which is reflected from the bottom of the eye, and 
suggested the circumstances under which the interior of the eye itself 
might be examined. It now appears astonishing that Mr. Cum- 
ming’s observations, leading not very remotely nor indirectly to the 
invention of the ophthalmoscope, did not at once excite more attention ; 
but it is perhaps still more wonderful that the mirror-like reflexion 
from the bottom of the eyes of cats and other animals, which must 
have been seen by the learned and unlearned, almost ever since 
the creation, should not have suggested the idea long ago: for 
