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What are Bifocals?
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  • Written By: J. Beam
  • Edited By: Niki Foster
  • Last Modified Date: 31 January 2012
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    Conjecture Corporation
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Bifocals are a type of prescription eyeglasses designed for people who need both near and farsighted vision correction. Different from single vision lenses, bifocals have two corrective lenses on each side of a pair of glasses, for a total of four lenses per pair.

Many people wear single vision corrective lenses for a number of years until their vision changes and they require bifocals for total vision correction. However, there remains a misconception that only aging people require bifocals. While its true that a person’s vision may change with age, requiring a switch from single vision lenses to bifocals, many people suffer from a combination of near and farsightedness long before they realize it. In some cases, bifocals can also help correct astigmatism that is present in combination with other refractive defects.

There are a few different types of bifocals, and a licensed optician can help patients with a prescription choose the best kind for their needs. Developments in the engineering of bifocals have been made over the years to eliminate the lines in many corrective bifocals. Progressive lenses, for example, correct vision at different powers depending on where one looks through the lens, but the lines are absent.

Though most people who require bifocals have difficulty focusing on objects both up close and far away, bifocals have always been designed with the corrective lens for close range focusing at the bottom and the corrective lens for distance vision at the top. While this design once made sense, because close range focusing was generally required for reading and writing, activities traditionally preformed while looking down, more and more people find it awkward to use bifocals with a computer. Since the computer monitor is directly in front of the user, the up close corrective lens seems out of place on some bifocals.

There are new lenses in development to correct this common problem, but in the mean time, many people who require bifocals have found that contact lenses are the best option for their vision correction. There are many advantages to wearing contact lenses rather than glasses. The primary advantage contact lenses provide is improved visual acuity. Contacts provide better peripheral vision and eliminate the need to adjust the angle of the head for computer use.

Not all vision problems can be corrected with contact lenses, but consult your optometrist or ophthalmologist if you would like to change from your current bifocals to contact lenses. Because visual acuity can change over time, it is important to have your eyes checked at a minimum of every two years.

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claire24
Post 4
Who would have thought that all of the technology we have these days, would affect something like the design of bifocal eyeglasses?

It makes perfect sense though -- as I type this I am looking directly at my computer screen. I can imagine how hard it would be to do this while wearing bifocals. You would probably have to hold your head at a weird angle. And, ironically, that could probably result in a whole different medical issue if you were to do it often enough.

rosoph
Post 3
I had no idea that bifocals could help people with astigmatism. How is that possible? I have an astigmatism, but I have no problem seeing things up close, so how would bifocal glasses help me?
anon7146
Post 2
I want to get a smaller pair of glasses but people have told me because the bifocal is up higher than with larger glasses that it makes your eyes look magnified.

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