subject: What Contact Lenses And Glasses Do To Us [print this page] The Florentines were probably mistaken in supposing that their fellow citizen, Salvino degli Armati, was the inventor of the lenses now so commonly worn as glasses and contact lenses, to correct errors of refraction (and poor eyesight).
There has been much discussion as to the origin of glasses and contact lenses, but they are generally believed to have been known at a period much earlier than that of Salvino degli Armati. The Romans at least must have known something of the art of supplementing the powers of the eye, for Pliny tells us that Nero used to watch the games in the Colosseum through a concave gem, set for that purpose in a ring. If, however, his contemporaries believed that Salvino of the Armati was the first to produce these aids to vision, they might well have prayed for the pardon of his sins.
While it is true that eyeglasses and contact lenses have brought to some people improved vision and relief from pain and discomfort, they have been to others simply an added torture, they always do more or less harm, and at their best they never improve the vision to normal.
That glasses cannot improve the sight to normal can be very simply demonstrated by looking at any color through a strong convex or concave glass. It will be noted that the color is always less intense than when seen with the naked eye, and since the perception of form depends upon the perception of color, it follows that both color and form must be less distinctly seen with glasses than without them. Even plane glass lowers the vision for both color and form, as everyone knows who has ever looked out of a window.
Women who wear glasses or cheap contact lenses for minor defects of vision often observe that they are made more or less color-blind by them, and in a shop one may note that they remove them when they want to match samples. However, if the sight is seriously defective, the color may be seen better with glasses than without them.
That glasses must injure the eye is evident from several observations. One cannot see through them unless one produces the degree of refractive error which they are designed to correct. But refractive errors, in the eye which is left to itself, are never constant. If one secures good vision by the aid of concave, convex, or astigmatic lenses, therefore, it means that one is maintaining constantly a degree of refractive error which otherwise would not be maintained constantly. It is only to be expected that this should make the condition worse, and it is a matter of common experience amongst opticians that it does.
