There have been both fortunate cases and unfortunate cases of using bifocal readers glasses during the past two hundred years after the invention of these vision corrective devices. First let’s review some primary aspects of this type of eyeglasses. Also known as bifocals or bifocal readers, bifocal reading glasses were originally invented by the innovative American statesman Benjamin Franklin to gain vision correction against both nearsightedness and presbyopia, which bothered him at the same time in his older years. This great creation has been utilized by countless followers to achieve nearly the same effect of eyesight compromise. Until now, these helpful devices have been around for so many years. But for the later comers or users, there are some necessary points to be known about these glasses.
The words typed above mainly focus on the upside of bifocal readers glasses. They are undeniably the truth. Bifocal glasses do help those with nearsightedness as well as presbyopia gain normal vision without much effort. This means of vision compromise costs less expense compared with two separate pairs of prescription glasses. Of course, the freedom from pairs of eyeglass switches still enables the presbyopic patients to enjoy favorable activities more conveniently. This is to a large degree another advantage of wearing bifocal reading spectacles, compared with using regular reading glasses. These advantages have helped bifocals lure a very large number of wearers.
To be honest, there is still the downside of bifocal readers glasses. Each pair of traditional bifocal reading glasses has been made with a visible line across the middle part of a lens. Apart from the functional benefits brought by these lenses, there are obvious or even serious shortcomings caused by this lens design. On one hand, this clear separation of vision sections may cause easily image jump while a user tries to make visual switches at different ranges. On the other hand, the visible line on a lens will surely offset the wearers’ natural eye beauty.