Trifocals are like three pairs of glasses in one. Trifocals will provide you with three vision segments, as the name suggests. It may sound challenging to adapt to a pair of trifocals, but it is actually failry simple. Trifocals will offer more visual convenience than bifocals after you have adjusted to them. You can consider this similar to climbing up steps. Rather than jumping straight up to step three, it is easier to use step two. Your eyes will love being able see clearly at three distinct zones.
Rather than prescribing a simple bifocal, people with advanced presbyopia are usually advised to get trifocals from their optician. This is because more advanced presbyoes benefit from a multiple range of corrections. During your eye exam, the doctor will be able to determine what your eyeglass refraction is. The unit of measure used to write an eyeglass prescription is called a diopter.
Bifocals can offer correction only at two ranges of distance, that is to say, near vision or distance vision. Trifocals will offer correction at all ranges of distance. This is the reason trifocals can provide the most clarity at varying distances.
Trifocals are a fantastic option, but for many may be over the top. While not required for all presbyopes, trifocals will satisfy a varying range of visual demands. Most people find the intermediate distance segment the most difficult to adapt to. A spectacle Rx of -4 diopters with a reading add of +3 will produce a reading segment of -1. Given these values, the mid-range correction will be a -2.5.
Trifocals offer a greater range of intermediate and near vision when compared to bifocals. They give you three areas of correction, like a bifocal but with built in intermediate vision.
The lower section of the lens is the portion that will contain the near range of vision correction. The line on your lenses can vary in shape based on your visual demands, your optician can help you decide. The varying segments of the lens are clearly marked with a very thin, yet visible line.
The absolute near vision is corrected by a segment on the bottom of the lens. When fit properly any of these eyeglasses are very easy to adapt to.
The portion of the lens that corrects intermediate vision is directly on top of the full near vision part of the lens. This will not cover the greatest range, intermediate vision is usually described as 2-5 feet from your eyes while near vision is 16 inches.
With a single pair of trifocals, you can tackle all problems related to presbyopia. You might encounter a problem with the lines of demarcation in these specs. If this sounds like you, you may love progressive eyeglasses. They will correct your vision just as well as trifocals. In fact, they are more comfortable as the vision zones are not demarcated with a line. They will give any presbyope the best possible vision.