If you are 40 years of age or older, you may be having difficulty with close-up vision. This is a natural phenomenon that occurs as people mature. The medical name for it is presbyopia, and the condition is caused from thickening and reduced flexibility in the lens of the eye. Age-related presbyopia affects everyone, even people with myopia, or near-sightedness--the inability to see things at a distance. The good news is that bifocal reading glasses will correct this vision problem.
Non-Prescription Readers
Inexpensive reading glasses are available in any drug store or discount department store. The problem with full-frame readers is when you put them on and you can see close-up, but everything else is out of focus. Half-frame readers include only the magnification portion of the lens and are designed to fit lower on the bridge of the nose. The wearer raises his eyes above the lens to see distant objects. Bifocal reading glasses separate the lens into two parts: a clear lens for moderate to distant vision at the top and a magnifying lens for reading and task work at the bottom. These types of quality, non-prescription readers have many of the popular features of prescription eyeglasses. They are made of lightweight, distortion-free, optical quality plastic that is scratch-resistant and UV coated for protection from harmful, ultraviolet rays. Line and no-line bifocals come in a wide assortment of fashionable frames including designer styles. Folding versions are convenient to carry for ready use. Tinted sun readers are also available. Purchase top quality bifocal readers at high end department stores or specialty shops and from online merchants.
Prescription Bifocals
Unless you wear contact lenses to correct myopia, astigmatism or other vision problems, you will not be able to purchase non-prescription bifocal reading glasses. Your eye doctor will prescribe a combination lens especially for you. In the past, lined bifocal eyeglasses were a telltale sign of the wearer's age. Those "Franklin" or "E-style" bifocals had an obvious line all the way across the lens separating the focal strengths of the lenses. Newer bifocals feature only a small area of corrective lens for close vision. The near vision correction can be round, crescent or ribbon-shaped and is usually positioned within the total lens to align with the wearer's lower eyelid. Although bifocals typically have a line of demarcation between the focal strengths, E-Z-2-Vue lenses are designed to be less obtrusive.
Multifocals
Trifocal eyeglasses correct distance, intermediate and near vision with three zones. The intermediate zone aligns with the wearer's pupils and enables straight forward vision at objects 18 to 24 inches away. The upper portion of the lens is for viewing objects at a distance; the lower portion is for viewing objects up close. Progressive addition lenses, or PALs, provide smooth, no-line transition between all focal strengths. Progressives afford comfortable vision at all distances. If you work at a computer, progressive lenses with an anti-glare coating are ideal.
Some occupations require special multifocal lenses. The Double-D lens, which features two crescent-shaped bifocals instead of one, is perfect for car mechanics and others who need sharp close-up vision above and below their central line of vision. E-D trifocals separate the top half of the lens for distance and the bottom half for intermediate focus. A crescent-shaped lens for near vision is embedded in the lower, intermediate zone. These multifocals are ideal for people who must shift their focus in many different areas. Occupational lenses are intended only for work or hobby use.
