How Do Bifocals Work?

It is not uncommon for people to have both myopia and hyperopia. Myopia is the scientific name for nearsightedness whereby an individual is able to see near objects clearly but will have trouble with those at a far distance. Hyperopia denotes farsightedness as a person is only able to see things at a distance. If a person has eyes that are both farsighted and nearsighted, they have presbyopia.  This condition develops as a person ages and some of the typical symptoms are inability to see print up-close.  Eye doctors recommend bifocals to correct presbyopia.  So how do bifocals work? Below is a simple guideline.

Equipped with two areas of correction

Invented by Benjamin Franklin, bifocals are simple lenses that have evolved over time.  Commonly referred to as reading glasses, these lenses have both a top and bottom portion. A traditional bifocal lens will usually have the distance prescription in the entire lens while the ADD power will be placed at the bottom of the lens to correct nearsightedness and enhance reading.  Others will have a separate top and bottom portion with a visible line separating the two. The top part of the lens helps you to see things from a distance while the bottom part is for up-close vision.  The beauty with bifocals is that they give the eyes a near perfect vision, which is equated to 20/20. This simply implies that you are able to see objects that are 20 feet away clearly.

Modern bifocals

For cosmetic reasons, a blended segment of bifocals have emerged over the years. One outstanding feature of these lenses is that they do not have a visible line separating the two portions. They are commonly referred to as progressive or no- line lenses.  The lenses have a smooth change from the top, middle and bottom portion. The top part of the lens is for distance, the middle part is to enable the wearer to read things at an arm's length while the bottom part is for close-up vision. These progressive lenses have a column of clarity, which has an hourglass shape that accommodates the three sections. Unlike, traditional bifocals, these progressive lenses are more natural and smooth, as the vision is continuous with no line or unsettling image jumps as you move from one section to the other.     

A good number of people experience presbyopia as they age. There is no need to worry as the eye doctor will prescribe traditional bifocals or progressive lens to correct this vision problem.  All you need is a little bit of time to adjust your vision to the different sections of these reading glasses and you are good to go.

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