Among individuals over 40 and 50 years old, it is a common practice to stretch the arm to the limit when they try to read up-close materials. Placing a book, newspaper or menu at a normal distance will only lead to a blurry effect. This is very probably the symptom of presbyopia, an age-related vision problem. Like other groups such as the myopia, the hyperopia and even the astigmatic, patients suffering from presbyopia also need to rely on external help or vision aid. Otherwise normal reading is impossible. The solution to presbyopia through corrective eyewear is usually magnifying glasses. It is not difficult to see a senior reading a newspaper with a pair of glasses. Similar to myopia glasses and hyperopia glasses, magnifying eyeglasses are also magic that they can “bring back” normal, clear vision for presbyopic patients.
It is worth stating that presbyopia is a vision condition essentially different from myopia and hyperopia. While the latter two conditions are caused by abnormalities in eyeball shape and are called refractive errors, presbyopia is closely related with the natural lens’ aging and loss of elasticity. As a result, magnifying glasses function in a considerably different way from nearsighted and farsighted eyeglasses. Another difference between magnifying eyewear and glasses for refractive errors is that the first type can be got without a prescription. Pre-made of pre-fabricated magnifying eyeglasses are widely available over the counter. In the 1990s, ready-made magnifying spectacles became extremely popular that over 30 million pairs were sold. This medical practice is completely different from the purchase or selling of myopia and hyperopia glasses which require strictly a valid prescription.
Magnifying glasses have been highly expanded in form of lens power. The most traditional form is regular reading glasses whose whole lenses are equipped with a reading prescription. They are the first choice for people who spend a great deal of time concentrating on near reading. Multifocal forms of magnifying eyewear are thought to be more powerful because they can deal with several conditions within a single pair. Bifocals, trifocals and progressives are currently available.