What are multifocal contact lenses?
Multifocal contact lenses (also known as varifocal contact lenses) are designed to correct vision changes that occur with presbyopia. You may already be familiar with this term, but essentially presbyopia is the correct term used to define a perfectly normal change within our vision which changes our ability to focus on near objects. It's frustratingly normal but leads to the need for multiple different prescriptions. Multifocal contact lenses have been specifically designed to address this need for different prescriptions and maintain clarity in all aspects of vision.
Are multifocals and bifocals the same thing?
Multifocals and Bifocals are quite different! In the broadest sense, the term multifocal refers to 'multiple' focus distances whereas bifocal refers to just 2 defined prescriptions. A multifocal contact lens is sometimes referred to as a varifocal contact lens to mirror the terminology used with spectacles. As with glasses, a bifocal lens may be able to provide clear vision in two focal ranges, traditionally 'distance' and 'near'. However, so much of our world today sits in the 'middle' of these focuses! Consider a computer screen, a newspaper, a car dashboard or even your dinner plate...a bifocal may not ensure clear vision in these areas. Multifocal technology advances beyond this, providing multiple focal distances to create clarity over a wide range of distances, incorporating this important middle focus zone.
How do the multifocal contact lenses work?
Multifocal contact lens technology has advanced significantly over the last few years. As with most prescriptions, both rigid gas permeable (hard) and soft lenses are available in multifocal corrections. Soft lenses make up most of the current market and it is here that there have been the biggest advances. There are many different designs or types of multifocal contact lenses but the most common use a principle of simultaneous vision. In essence, this means that the eye is seeing through all prescriptions at the same time!
Whilst this may sound impossible, the visual system adapts well. Consider a windscreen with rain drops on it, or a shop window with your reflection in it. In both instances, you can choose to focus on the near element (the raindrop or reflection) or focus through this into the distance (the road or contents of the shop). Both images are in your vision but you can choose where to focus. Multifocal contact lenses can be thought of in a similar way, all images are seen, but you learn to choose which to concentrate on!
Why should I opt for multifocal contact lenses?
Any patient requiring a near correction could be successful in multifocal contact lenses and presbyopia should not mean the end of successful contact lens wear. Existing contact lens wearers can easily progress into multifocals when presbyopia arrives and they notice near focus changes in their existing lenses.
Patients new to any visual correction can also benefit from multifocal lenses. Contact lenses provide a freedom of vision akin to returning to having no correction at all and enable the feel of a return to 'natural' vision. Multifocal contact lenses provide an excellent alternative to 'reading glasses' and the inconvenience that they can bring!
What are the advantages to multifocal contact lenses over ‘monovision’
Monovision is a term used to describe wearing one contact lens in one eye to correct near vision and a lens in the other eye to correct distance vision. Multifocal contact lenses correct near, intermediate and distance vision in each eye. The clear advantage with a multifocal contact lens choice is the ability to use both eyes together as nature intended! Using a multifocal lens enables both eyes to simultaneously see at the required distances. Maintaining the use of both eyes together helps keep our 'binocularity' or depth perception more stable. Alongside this, Multifocal lenses also provide areas of intermediate focus clarity, ensuring vision that is as close to natural vision as possible. Multifocal contact lenses ensure that all of the benefits contact lens wear provides can continue into the onset of presbyopia and beyond.
Are there any things to consider when opting for multifocal lenses?
The visual demand on a multifocal lens can be high and some patients may still occasionally find the need to supplement their contact lens wear with glasses for the finer details. Some patients can also take a little longer to adapt to this new way of seeing. Many multifocal contact lens designs work best for certain pupil sizes. If you were to fall outside of these parameters, you may find that the contact lenses do not work quite so well for you in all scenarios (fine detail reading or driving at night for example) Your Optician will be able to discuss this with you further if necessary. The 1-Day ACUVUE® MOIST Brand MULTIFOCAL uses advanced technology to modify its design to account for some natural changes in pupil size between patients and prescriptions increasing the chance of successful multifocal contact lens wear.