The Evolution of Refraction and Its Necessity

To the Editor:  —Notwithstanding the chaos that has apparently existed in medical literature and among ophthalmologists in reference to cause and effect of eyestrain, there has been evolved a well-defined consensus of opinion on the subject that to-day is recognized by the vast majority of the medical profession.It is as great an error to be blindly conservative as to be wildly radical in reaching conclusions deduced from new problems that have been presented to the ophthalmologist during the past twenty-five years. During the formative period, the period of investigation, there is no doubt that too many ocular muscles were cut; too much stress laid on the disastrous effects of eyestrain, but from this experience have been established well-settled principles of optics and treatment. We still make our tenotomies, we refract more accurately than ever before, but in doing either we are guided by clinical experience that has made us