Among the most common causes are the use of tobacco or alcohol, overuse, bad light, injury to the eye, and disease of the kidneys. These are among the most serious of eye disorders, being in many instances incurable. When resulting from the use of tobacco or alcohol, great improvement generally occurs from the disuse of narcotic stimulants of all sorts. The use of electricity is a valuable remedy in many of these cases. There is a peculiar form of disease of the retina in which it becomes covered more or less densely with black spots. A prominent symptom of this disease is night blindness. Patients thus affected are able to get along without difficulty in the daytime, but become partially blind after sundown. There is also a narrowing of the field of the eye, so that objects are seen distinctly only when directly before the center of the pupil. Little can be done for these cases by way of treatment.

Diseases of the Optic Nerve

When the optic nerve is seriously diseased, a considerable or complete loss of sight is generally the result. It is subject to inflammation, paralysis, and atrophy. The use of tobacco is a very frequent cause of these affections. The treatment is the same as that suggested for diseases of the retina.