Bifocals and Trifocals – See clearly with just one pair of glasses
You can often spot a person who needs multifocal lenses from across the room. They’re the ones squinting to see the menu board with their reading glasses tucked in their pocket or the ones with their regular glasses on, trying desperately to focus on a paper in their hands. In the past, these people would have had very limited options, but now they can rejoice, because there is a lot more to choose from.
As you age, your eyesight changes and so does how your eyes work. The natural lenses inside your eyes stiffen, making it harder to focus, and the muscles in your eyes don’t work as well as they used to. You may need help because you no longer see clearly close up or far away. One aspect of your prescription may have stayed the same, but the other may have worsened. Regardless of how or why, there are different needs for seeing different things. Unless you want to carry several pairs of glasses in an oversized bag, you need a single pair that can help you achieve the most optimal vision in all of the vision fields.
Of all of the multi-focal lens types that are prescribed, the bifocal is the most common. These lenses offer clear vision at two distances, near and far. Who would benefit most from a bifocal lens? Those who do a lot of reading or up close work that they might not be seeing as crisply as they could.
Trifocal lenses are those that give vision assistance in three fields of vision including near, middle and far. The middle zone or intermediate vision field is most likely associated with things that are about arm’s length away from you - think computer, for instance. One group of people who would benefit from trifocal lenses are those who frequently travel to places that they are not familiar with. Trifocal lenses would allow them to see the road in the distance, the maps or GPS unit and their car gauges all clearly, so they do not miss their turns or speed to their destination on an empty tank.
Special fittings for special lenses
When you are prescribed bifocals, they must be precisely fitted for the best possible vision. The optometrist will measure very carefully, aiming to have the line of the bifocal at the height of the lower eyelid. Trifocals get fitted a little differently, a little bit higher than the bifocal line. A trifocal puts the upper part of the intermediate correction at the pupil level. There are some bifocal types that have a more blended appearance so that the division is not as visible. No matter which type of multifocal lens you get, make sure that they are fitted well so that you get the best vision correction possible.
Sometimes, you may find that you have trouble seeing during a particular job or hobby. Don’t let your vision stop you from enjoying your pastimes or from performing the best that you can at work, discuss your needs with your eye care professional. You might need vision correction in addition to your usual prescription. Your doctor can prescribe special glasses that would not be worn every day, but just during the specific activity you are having trouble with. In some cases, Multi-focal lenses might be the answer that you need. There are several types of these occupational lenses including the Double-D which is a bifocal and the E-D which is a trifocal lens.
Double D bifocal lenses are good for those who are working with close-up work as well as needing to see above their heads. Drywallers who must work with measurements as well as look up to line up their work are a good example of this type of need. A trifocal lens like the E-D is good for those who are doing work close up, in the intermediate area and at a distance. Someone who is working on the computer, taking notes but still needs to be able to see people across the room could benefit greatly from these.
Bookmark This Page