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                                       DEPTH of FIELD

                                       CONTACT LENSES

                                                                    Making Contact

                                                                 By Shirley Ha, BSc. (Hons), O.D.

                      ethods for correcting presbyopia have evolved significantly since  To understand the EDOF optics, a lesson
                      the first double spectacles were invented by Benjamin Franklin   on the basics is in order. There are two
                      in the late 1700s. In recent years, there has been a paradigm shift  types of simultaneous image designs. They
                      in what eyecare professionals are recommending/prescribing   are either zonal, with distinct annular
        Mand what consumer presbyopes are asking for when it comes to  zones of distance and near power

         presbyopia.  Along  with  a  tucked, lifted,  augmented  and  toned physique,  many  surrounding a primary viewing zone in the
         active presbyopes with fading vision at near would now like to be spectacle-free  centre of the lens, or aspheric, with the lens
         or continue wearing contact lenses as they age. They are looking for alternative    power gradually changing from distance to
         management options, including an introduction to, or a transition into, soft     near (or near to distance) from the centre
         multifocal contact lenses (MFCLs).                                  to the periphery of the lens, similar to
         Did you know that the most commonly  Multifocal EDOF® (SynergEyes). The  progressive add lenses. The visual result

         prescribed MFCLs are soft simultaneous  BHVI’s original goal was to design a  with the limited focal depths comes from
         image designs? The latest version comes   MFCL  that  can  expand  the  depth  of  the pupil size changes in different lighting

         from the Brien Holden Vision Institute   focus and provide optimum image     conditions, and/or associated different power
         (BHVI) in Sydney, Australia, where   quality across a range of viewing    zone sizes. Some use a distance-centred
         their proprietary design, the Extended                              lens for the dominant eye and a near-centred
         Depth of Focus (EDOF), is now found   distances. Current simultaneous image   lens for the non-dominant eye. Others use
         in at least three EDOF contact lenses:   designs with two focal points cannot do   the differences in the size and/or power of
         SEED®1dayPure (Japan), NaturalVue®    this. With EDOF designs, there will be   the optic zone for the ADD, with a larger
         Multifocal 1 Day (Visioneering   multiple focal points along the visual  ADD on the non-dominant eye; yet others

         Technology), and SynergEyes iD hybrid  axis providing clarity at every distance.  use the same optic zone size and push plus

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