Multifocal lenses are lenses designed to correct Presbyopia, whilst giving the wearer clear distance vision at the same time. A simplified explanation would describe them as working like a traditional bifocal lens, offering clear distance vision at the top with the reading prescription at the bottom of the lens, but unlike bifocals, they offer an arm’s length (or middle) focusing distance as well, and there is no visible line delineating the different parts of the lens.
This “no line” Progressive lens design makes it easier to walk around in as there is no bifocal line to get in the way when looking down. Multifocal lenses are by far the most popular design of lens for spectacle wearers who need extra reading help (usually once they reach about 45 years- a condition called Presbyopia and explained in the link below). At Personal Eyes Optometrist Sydney CBD office we would prescribe this modern lens design at least 20 times more frequently than its bifocal equivalent.
The Progressive (or Multifocal) lens design was first patented in 1907 but it was not until 1959 that it was commercially available, when Bernard Maitenaz a French Optical Engineer working for Société des Lunetiers (Now Essilor) released the first Varilux lens.
In the sixty years since the first Varilux lens was released, the design has been continually updated, reducing and removing the distortions of the vision (aberrations) that plagued the early lenses, which restricted the clarity of the peripheral vision and gave a narrow reading area.
Essilor, the original manufacturer, has been joined by a host of other lens companies, and the modern consumer can now choose from hundreds of multifocal designs from the world’s leading lens manufacturers including Carl Zeiss, Rodenstock, Hoya and Nikon.
The qualified staff at Personal Eyes Optometry can advise you on which of the bewildering range of multifocals is most suitable to your needs.
It was only recently, with the development of computer-controlled “freeform” lens generating machines, that theses multifocal lenses could be customized allowing our Opticians at Personal Eyes Optometry to specify the proportions of the Multifocal lenses, enabling us to design your lenses to have a larger reading or intermediate area.
These customized multifocal lenses are particularly useful to the large number of Sydney CBD office workers who spend long periods of time staring at computer screens. They alleviate the need to lift your head when reading a screen, and continually turn the head to keep it in focus. These specialized multifocal lenses are often referred to as vocational multifocals and amongst their designs are the
Rodenstock Ergo, Hoya Workstyle, Zeiss Officelens and Essilor Interview.
At Personal Eyes Optometrist, quite often these customised multifocal lenses are treated with a blue light filters as a large portion of our Sydney CBD cliental work with computer screens, and there is some concern about the effects of excessive exposure to the blue light emitted from digital devices. This subject is discussed in some detail elsewhere on this website and there is a link below from The Harvard Medical School’s report on blue light exposure.
For some people, the size of the distance vision area is more important, and their particular requirements can met by customizing their multifocal lenses with a smaller reading area that is often also fitted lower. This design of progressive lens is particularly useful for sports or bushwalking.
As you can see, there are many different options available for multifocal lens designs and the Optometrists at our Sydney CBD office are well versed in solving the needs of multifocal wearers including customizing the design of these lenses to suit everyone’s needs.
http://www.optometry.org.au/your-eyes/your-eye-health/eye-conditions/presbyopia.aspx
https://www.health.harvard.edu/staying-healthy/blue-light-has-a-dark-side
https://www.rodenstock.com/com/en/computer-spectacles.html