Benjamin Franklin invented bifocal glasses in the 1700’s. However, the first eyeglasses were invented centuries earlier. The first eyeglasses, invented in the 13th century, had convex lenses that magnified objects in order for people to see them more clearly. Convex lenses were used to correct farsightedness, the inability to see items clearly that are nearby, such as when reading. During the 14th century, concave lenses were invented. Concave lenses are used to correct nearsightedness, or the inability to focus on object in the distance.
Benjamin Franklin has problems focusing on objects both near and far. During his many travels, he would often want to read, and since he wore his concave lenses most of the time, he would find himself having to continuously swap eyeglasses. During those times, lenses were shaped like a half-moon rather than the round lenses that we are accustomed to. In an effort to eliminate the need to continuously switch eyeglasses, Benjamin Franklin combined the lenses into one lens – the top half for viewing things at a distance and the bottom half for viewing things close up. Bifocal glasses simply mean that the glasses of used to correct two vision problems rather than one.
Today, more than half of the people that wear corrective lenses wear bifocals. Bifocal glasses are prescribed for people who have more than one vision problem, such as the problem that Benjamin Franklin had, in an effort to eliminate the need for more than one pair of glasses. Many people who have worn single lens glasses find that, as they age, they may be required to wear bifocals. It may take some time to get adjusted to your bifocals in the beginning, but the only alternative is having more than one pair of eyeglasses, and switching back and forth as you change activities.
Whether you wear single lens eyeglasses or bifocal glasses, you can purchase your glasses from the comfort of your own home at significant savings over brick and mortar retailers. Of course, before ordering any type of glasses, it is important that you obtain an up-to-date prescription for your lenses. As we grow older, our vision may change rapidly. Prescriptions for eyeglasses should not be used for more than two years. Once you have your prescription, ordering online is a simple process. It is important to get the correct measurements for your frames. The measurements can be found on the eyeglasses you are currently wearing. Purchasing eyeglasses does not have to be the expensive undertaking of the past. Online retailers sell the same quality products for a fraction of the cost, making it possible for people of all budgets to be able to afford the glasses they need to improve their vision.