The terms Progressive Addition Lens (PAL), no-line bifocal, and no-line trifocal are all synonymous for the same type of lens. Typically, a PAL is prescribed to give the patient the best distance, intermediate, near, and “everywhere in-between” vision possible. There is a gradient of lens power that starts at the patient’s distance power towards the top of the lens, and gradually increases towards the bottom where it reaches the maximum reading power.
PALs are frequently prescribed for patients that start to notice the effects of presbyopia, a condition where the eye loses its ability to focus well on objects that are near. The effects of presbyopia naturally start to affect most adults in their early 40’s.
PAL lenses are priced much higher than single-vision lenses made from the exact same materials. The reasons include increased manufacturing costs, more research and development required for each specific design, lenses needing to be “remade” more often due to patients not adapting or an error in the more complicated manufacturing process, and the optician fitting the glasses requires more skill.
Most optical stores will offer more than one style and price-point of PALs. Good/Better/Best options are typical in discount type stores, while higher end stores may offer a variety of designs from multiple lens manufacturers. A well trained and quality optician knows the advantages and disadvantages of the PAL designs and brands available, gets to know the visual needs and lifestyle of the patient, and can make a good recommendation.
The major brand names for PALs in the United States (and the type of optical store where you can typically find them) are Essilor (Costco, Pearle Vision, Lenscrafters), Kodak (Walmart, Sam’s Club), Zeiss (Retail and Independent), and Hoya (High-End Retail and Independent). My office has a 25 year relationship with the local Hoya supplier and we have found that they provide the highest quality lenses, materials, and workmanship in our area. Hoya provides most of our lenses, but again, we do still work with other brands when a patient has a visual need where a Hoya lens design may not be optimal.
|Note the differences in distortion|
The latest PAL designs are marketed as “Free-Form”, “High definition”, or “digital” designs. True free-form surfaced PALs offer significantly less distortion, especially towards the edges or periphery of the viewing areas. I have seen many discount shops marketing non-free-form designs as “High-Def”, etc., and would recommend that you insist on knowing what brand and design you are truly getting. That being said, certainly the very basic inexpensive PAL designs can work quite well for the non-discerning or “low-vision” patient. For example, I will recommend seeking out the inexpensive designs for a patient with some sort of ocular disease (like early macular degeneration) where spending more money on a better free-form lens simply will not make a subjective difference.
The bottom line is that PALs are a much more complex optical lens than a single vision lens and are typically a larger investment. My advice is to find an experienced licensed optician (the state of Illinois does NOT require opticians to be licensed or certified) that you can trust. I personally believe that all opticians should have ABO certification. I employ accordingly and encourage my colleagues to do so as well.
Dr. Andrew Neukirch is a primary care optometrist. He is therapeutically certified to practice medical optometry in the states of Illinois and Indiana. He is CEO of Carillon Vision Care and practices in Glenview, Illinois. Dr. Neukirch is a Member Director of the Independent Doctors of Optometric Care, a large network of providers working together to make their patients’ care and experience the best possible.