What Are Progressive Lenses?

First, what is Presbyopia?
 

Presbyopia is the normal loss of ability to focus clearly on near objects that comes with age. Traditionally, people have to wear conventional bifocals with visible lines across the lenses that broadcast your age, but with progressive lenses, this is no longer the case.
 

Progressive lenses, also known as progressive addition lenses (PALs) or “no-line bifocals”, are true multifocal lenses. They provide a seamless transition between your eyeglasses prescription in the top half of the lenses and the added magnification (near “add”) for reading, in the bottom half of the lenses.
 

Why Choose Progressive Lenses?
 

Not only do they provide a more youthful appearance, the line-free progressive lenses provide a more complete and natural correction of the symptoms of presbyopia.
 

Here’s the best part: progressive lenses have no annoying bifocal line.
 

Instead of just two (“bi-focal”) or three (“tri-focal”) lens powers, progressive lenses all have a seamless progression of lens powers for all viewing distances. This eliminates the “jump” that appears when your eyes move past the sharp boundary between the distance and near parts of your lenses.
 

Also, when wearing properly fitted progressive lenses, you can see clearly across the room and farther away without having to move your head. You can look up to see far away clearly and look down to easily read or complete other close-up activities.
 

Limitations of Progressive Lenses
 

No multifocal lenses in the market can reverse the symptoms of presbyopia or perfectly replicate your eyes’ natural ability to quickly change focus when viewing objects at all distances and directions.
 

Some limitations of progressive lenses include:
 

1. Reduced near and intermediate fields of view.
 

While modern progressive lenses produce a very wide field of view for distance vision, in order for multifocal lenses to contain lens powers for multiple viewing distances without visible lines there is a tradeoff. This tradeoff is that the lateral visual field of the intermediate to near portions of progressive lenses is much smaller than the field of view that non progressive bifocals and trifocals can provide.
 

To better explain this, the visual field that is provided by progressive lenses looks roughly like an hourglass shape. The top half of the hourglass (the distance zone of the lens) is much wider than the bottom half (the reading zone), and the narrowest portion in the middle (the intermediate zone).
 

2. Sensation of movement.
 

Some wearers of progressive lenses experience a sensation of movement through the bottom half of progressive lenses during head movements.
 

This particular problem has been reduced significantly with new “digitally surfaced” or “freeform” progressive lens designs and fabrication technology.
 

3. Frame size limitations. It’s important to choose eyeglass frames that are large enough vertically to accommodate the “hourglass” lens design. Because progressive lenses vary in power from top to bottom, if the eyeglass frame is too small, the “reading zone” of the lenses could be eliminated when the lenses are cut to fit into the frame.
 

This problem, however, has been reduced by new progressive lens technology which accommodates smaller frame sizes.
 

4. Not ideal for prolonged computer use.
 

Most progressive lenses are not ideal for prolonged computer use because of the narrow field of view seen in the intermediate viewing zone of the lenses. Although acceptable for short-term viewing of a computer screen, this could be an issue for prolonged computer screen use.
 

If you experience presbyopia and work in front of a computer screen for hours at a time, ask your eye doctor about single vision or multifocal “computer glasses” that provide a wider and more comfortable viewing zone for prolonged computer use.
 

How to Adapt To Your New Progressive Lenses
 

When you are fitted with your first pair of progressive lenses, you may experience a short adaptation period before the lenses become fully comfortable. This could take a few minutes, all the way up to a few days.  It’s important to know that during this adaptation period, your comfort levels will improve significantly as you become adjusted to the head positions that provide the best viewing angles for your eyes. Almost all users of progressive lenses adapt very easily, with wearer satisfaction well over 90%.
 

If you do have problems wearing progressive lenses comfortably after a week or two, see your eye care professional for troubleshooting.