It is not generally understood by those depending on artificial assistance to enjoy good vision, that it requires AS MUCH SKILL AND SCIENTIFIC KNOWLEDGE, to properly adapt a pair of spectacles, as it does to prescribe proper medicine, and that there is as much injury done to the eye from the use of improper medicines. A pair of spectacles should never be purchased from any person who is not thoroughly acquainted with the anatomy, physiology and disease of the human eye, laws of light, and the science of Optics. Yet it is strictly true, that a full knowledge of the above, combined with skill and experience, is absolutely necessary to CORRECTLY ADJUST TO THE EYE a pair of spectacles. The principle causes of optical defects of vision generally arise from decrease or access of refractive power in one, or more or all, of the transparent parts of the eye. In the presbyopic (or aged) eye, a magnifying lens is required. The myopic (or near-sighted) eye, a minifying lens. Now the great science of the Oculist or optician is THOROUGHLY TO UNDERSTAND THE AMOUNT of refractive power the eye has lost, or hAs in excess, so as to be able to select a pair of Lenses at once, at the first trial, that when tried by the patient shall prove to his satisfaction that they possess that amount of power the eye requires, NO MORE, NO LESS, or confidence ought not to be placed in his judgment. The usual method of persons wishing to supply themselves with spectacles is: They call at a deal's store, the proprietors of which places a number of spectacles upon the counter (of course, differing in degrees of magnifying power) from which the purchaser is to select. HE MAY just be accident, after trying a few pairs, take up a pair, and they may suit him as perfectly as if selected by the most competent Opticians; he sees well with then and places them aside from the rest. But not being sure of having the best pair amongst them, he endeavors to find others with which he can see still better! Spectacles after spectacles are tried, each sf [sic] different power, but with none can he see better than with the pair he laid aside. He tries that pair again, but is supposed to find he cannot see as well as when he tried them before. THE REASON WHY HE CANNOT IS PLAIN. The eyes possess the power for a moment of assuming the form necessary to see through any lens (at a certain distance from it) however improper it may be, and in the violent efforts it makes by endeavoring to see through the many tried on, has become nervously disturbed and excited, hence again cannot see through the spectacles that fitted the eye when it was undisturbed. The purchaser now, WITH EYES WEARIED AMD INFIT TO JUDGE of spectacles, tries a pair which seem to suit. These he buys, but soon discovers he cannot see with them as well as he expected. They make his eyes ache, and he remarks, “Why I could see beautifully with them at the store, and now I cannot” HE DOES NOT UNDERSTAND or take into consideration that his eyes have had time to recover form their excited condition by rest, and the spectacles that suited them in their distress, cannot suit them in their recovered state. He takes them back and goes through the same performance, until eventually becoming tired and out of patience of repeating the experiment (having no one of sound knowledge on the subject to advise with) he continues to wear the last pair he selected, thus forcing the sight to become (eventually) as DEFECTIVE AS THE POWER of such a lense requires it to be, in order to procure even ordinary eye-sight, and which spectacle sometimes in extreme nervous cases, CAUSE TOTAL BLINDNESS. The great difficult exists in finding an oculist or optician who really knows what kind of spectacles the eye actually requires, or the medicinal agents for the cure of its various diseases.

When we are obliged to hold small object further from or nearer to the eye, or try to obtain more light upon them than formerly, in order to see correctly; or if at minute employment, such as sewing, reading, writing, etc., the sight becomes dim, or small type of a book or newspaper on looking a short time (particularly by artificial lights) appears double, treble, indistinct or confused, with pain, ache or tiring of the eyes, or imagining we see small black, bright or colored spots floating before us, or clusters of threads, cobwebs, or other shapes and figures, or when the eyes are gradually losing their strength, shown by increasing dimness of vision; or when they are easily pained or dazzled by strong lights, such as are reflected from snow, water, vivid colored bodies, or the artificial lights of gas or lamps surrounding a speaker in public hall, or if the wind or cold makes eyes fill with tears, or if we occasionally see two or more objects where there is only one, or when we are obliged to rub or shut the eyes from time to time, look off from the work occasionally at other objects, before we can proceed with it. When any of the ABOCE SYMPTOMS OCCURE COLLECTIVELY OR INDIVIDUALLY, you ought to use spectacles, yet you had better apply to a professional man, who should be an optician, oculist and physician for advice respecting spectacles, as we have often weakness, dimness and other difficulties of vision, arising from some constitutional disturbances, perhaps located at some distant seat in the economy of he human system, exhibiting as one of its effects imperfection of sight, that can be frequently removed by Hygienic measures or medical agents. THE NUMBER OF CHILDREN AT SCHOOL SUGGERING in this way is immense. Being often abused for stupidity, both parents and teachers for a difficulty of vision, over which they have no control, and even obliged to wear spectacles, (sometimes) an exquisite torture advised by those who presume to know (when the article was really not needed). IT IS NOT UNCOMMON FOR CHILDREN TO REQUIRE OPTICAL AID in the form of spectacles at their studies; a remedy that when properly applies, only need to be worn long enough to remove the difficulty, as the eyes becomes as good as every, and the further use of the spectacles abandoned;-a circumstance rarely occurring in the aged, as their progress of sight is like their systems, on the way to decay, and dissolution, even this natural change of vision is much retarded by science by the admirable improvements in spectacles, and art in their proper adjustments.