"Taking up the diagnosis of the various forms of disease any of which would have been held to constitute the condition known as amaurosis, it may be noted, first of all, that even in the hands of the novice ophthalmoscopic examination supersedes those chapters in ophthalmology which were formerly devoted to the means of distinguishing between incipient cataract and amaurosis. In the past, and even at present, with those surgeons who are content to treat deep-seated diseases of the eye by guessing at their nature, and have not adopted the systematic use of the ophthalmoscope into their practice, the functional annoyances which commonly occur at the outset of the formation of lenticular cataract, have been, and are, fertile sources of deception. The patient complains of frontal pain, of confused vision, stars of light, and some other vague symptoms which characterize the outset alike of many forms of deep-seated disease of the eye, and of the fatty degeneration of the lens which commonly gives rise to lenticular cataract, probably from coincident swelling of the lens. An error arising from this source has many times condemned the unfortunate subject of a commencing cataract to the severe treatment thought appropriate to the unhappy class of amaurotics. The kind of alteration in the lens, imperceptible by any other means than the ophthalmoscope, is the slightly opaque striation of the substance of the lens sometimes seen in an early stage. These opaque striae may occupy either the anterior or the posterior segment of the lens, and spring from the centre of the crystalline or converge toward the centre from the circumference. In order to see the latter, the pupil must be fully dilated with atropine; as, indeed, for the purposes of complete ophthalmoscopic examination it always needs to be; and then, just as the greatest expert cannot discover them except by ophthalmoscopic illumination, so, neither with its aid, can they be passed over with ordinary care. In order to be quite sure in any delicate case, it is well to lower the light a little, and use only a feebly illuminating power, as a very strong light may overpower a {125} commencing opacity, and render us unable to detect the striae. This practical caution applies equally to all other conditions of opacity in the transparent media. In two cases, lately, I have been able to set at rest doubts of this kind, which happened to be in the persons of medical men, who were much disquieted by the symptoms--one a member of this society. In a third case I have recently detected incipient cataract (peripheric striae) in a gentleman supposed to be suffering from commencing glaucoma.