Without enough experience, some people may wonder what progressive eye glasses are. First of all, they belong to prescription spectacles which are used to deal with vision defects. Living in the modern society, an ordinary individual is quite likely to suffer nearsightedness at a certain age. Excessive eye use during school years is the common reason for myopia. In most cases, eye care practitioners would advise young patients with nearsightedness to wear a pair of prescription eyeglasses. With such a device, normal vision can be temporarily restored. They will still need to replace new lenses with a high power. In fact, these prescription glasses solely for nearsightedness are classified into the single vision category. Before age 40, it is enough for most individuals to use single vision glasses. But after such an age, the situation will probably change. Presbyopia usually starts to develop in folks in their 40s. This vision problem caused by natural aging in the eyes is associated with the decreased ability to focus close up objects properly. Presbyopic patients usually have to hold newspapers or books at an arms distance. This is the most typical symptom of presbyopia.
Yet what is the function of progressive eye glasses? Patients having both nearsightedness and presbyopia are really unfortunately that they can neither view clearly distant objects nor nearby materials. Progressive spectacles are a special solution to this problem. Single vision glasses are surely no longer feasible. Before the invention of multifocal eyeglasses, individuals with presbyopia had to keep two different pairs of single vision spectacles and switched between them on a regular basis. It was quite inconvenience to frequently make such kind of changes. In the modern market, such a concern can be resolved simply by wearing multifocal glasses. A pair of multifocal glasses incorporates more than one power in a lens. Progressive glasses are actually only one of the three categories of multifocal glasses. The other two categories are bifocals and trifocals. It is easy to understand bifocal glasses and trifocal glasses. The first type refers to glasses with two different powers equipped in a single lens. And a trifocal lens has three powers or focal points. Progressive eye glasses are more implicit that it is impossible to figure out the number of focal points in a lens. Actually, a progressive eyeglass lens has no permanent amount of powers. They are called progressive lenses because different powers change progressively in a lens. Unlike a bifocal lens or a trifocal lens, a progressive lens can offer progressive and natural vision correction.
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