21 AUGUST 1869, Page 24

The Theory of Ocular Defects and of Spectacles. From the

German of Dr. Hermann Schaller. By Robert B. Carter, F.R.O.S. (Longmans.)— This book is of too technical a character to be discussed in these columns, but we may briefly call the attention of our readers to its contents. It is a recent, or at all events recently applied, discovery in medical science that there are defects in the eyes other than the weaknesses of various organs in them ; that, to use popular language, they may be out of focus, and that these defects may be remedied by peculiarly-constructed glasses. A case has come under the writer's own observation in which the patient suffered from what appeared to be weakness of sight, and was treated, there being no visible cause, for depression or-general weak- ness of health, till it was discovered by an eminent oculist that there was something wrong, so to speak, in the arrangement of, the eyes. Glasses were constructed to remedy the defect, and the sight was imme- diately restored. It is perfectly certain that there are numbers of per- sons who still suffer in this respect from the not inexcusable ignorance of their medical attendants.