Mastering the Art of Progressives
Multi-focal Glasses
In the realm of eyeglasses, we all see how frames are constantly changing to reflect the latest fashion trends. Similarly, eyeglass lenses have also evolved with the times. This is especially true for multi-focal lenses, which are lenses that consist of 2 or more powers. Multi-focal lenses are useful for people over 40 years or those with accommodative difficulties to be able to use one pair of glasses to see at every distance.
There are various multi-focal options to choose from. The right option for you will depend on your lifestyle and what you would like to achieve with your glasses. Let’s review the top choices.
Bifocals.
Overtime, bifocal lenses have reshaped themselves into a thinner and lighter form. Today, the most popular bifocal is a flat-top design that has a near segment that is 28 mm wide. This design provides a large area for reading, while also keeping the segment line small enough to look attractive.
Bifocals, however, have a limitation. They offer great vision for far and near distances, but they do not accommodate for the intermediate (or arm’s length) distance.
Trifocals.
Trifocal lenses have an added segment above the near segment that provides the intermediate zone of vision, which ranges about 18 to 22 inches away.
This intermediate segment is ideal for computer use and seeing the dashboard while driving.
Limitations of Bifocals and Trifocals
Bifocals and trifocals may be functional, but they pose one obvious problem – the visible lines within their lenses. Some of us might view the noticeable lines as a sign of ‘aging’.
The lines in bifocals and trifocals may also cause a visual issue. As the eyes shift between each lens segment, the sudden changes in powers might cause an “image jump”. This effect can be difficult for some to adjust to.
The drawbacks of lined bifocals and trifocals have challenged science to invent a more modified multi-focal lens design. Hence, the progressive lens design has emerged and has been a breakthrough for many.
Progressive Lenses
Progressive multi-focal lenses (aka progressives or PALs) are the true definition of “multi-focal”. Instead of having just 2 or 3 powers, the progressive lens is composed of a gradual change in power from the top of the lens to the bottom, which allows it to incorporate a variety of prescriptions within its lens. This means that we can see clearly at distance, intermediate, near and everywhere in between. That too, with no lines whatsoever.
Since there are no visible lines or abrupt changes of lens powers in the PALs, it alleviates the sensation of “image jump”. We can comfortably and seamlessly transition among the different parts of the lens without sudden shifts in image position and size. As PALs have resolved the obstacles of the lined alternatives, they have become the most popular choice for multi-focal wearers.
Limitations of PALs
The #1 limitation of progressive lenses is the test of time.
Imagine riding a bike. The lines of bifocals and trifocals are similar to that of training wheels; they act as visual guides for how to use the lenses.
PALs are like riding a bike without training wheels. It takes time to adjust - a few days to 1 week. The more practice and patience given, the faster the brain learns how to use them. In no time at all, the biker will ride faster, more effortlessly, and with fuller range than when he/she rode with training wheels.
The Ideal PAL Design for You.
PALs are not a one-size-fits-all deal. For this reason, at SK Eyecare, we tailor our PALs to the individual. We offer a variety of lens options to choose from, each suitable for different specifications. For our present PAL wearers, we invite you to let us know of any difficulties you may be experiencing with your current pair of lenses. Having trouble looking for the sweet spots for each of the distances? Is the reading portion too small? We’ll work together to figure out your specifications to determine the perfect PAL design for you.
Our first-time PAL wearers receive training the day they pick up their glasses. We will be your training wheels and take your new lenses for a spin with you. We set time aside for you to show you the basics of how to use your new glasses to make sure you are seeing clearly and comfortably before stepping out of our office.