When wearing an appropriate correction they could see perfectly well, so what was all the fuss about? This fuss wasn’t just confined to my consulting room either, as presbyopic contact lens dropouts have been documented elsewhere as due to vision as much as the age-old comfort issue^1^.
Then I hit my forties, and multifocal contact lenses appeared. As a Contact Lens Optician and very longstanding contact lens wearer, I got very excited at the prospect, and immediately began wearing multifocals before I even particularly struggled with reading, because I wanted to understand more about presbyopic contact lens correction. Would I take a major hit in my distance vision? Would the near vision be good enough? Would it all go to pieces in dim light? Would the vision be stable? I have a bit of cyl in my left eye, so how would that affect things?
It turns out, all was fine. My distance was unaffected, as I had the smallest of reading adds, and I was wearing a multifocal design which had a very low entry level add. This meant the help with near vision was subtle, but that was all I needed, so I was still at a loss to see why presbyopes complain so much!
My reading add gradually increased during my forties, but trying a couple of different designs of multifocal contact lenses, I found one that met my needs nicely. As an anisometrope with -7.00 RE and -3.50 LE, I could easily read without my specs, so very intricate tasks were best accomplished unaided, and I didn’t bother with varifocal specs for a while.
Then I hit 50, and the strain began to show! Reading anything in my single vision specs became a thing of the past, and now even with my lovely multifocal contact lenses I occasionally need a bit of a boost, if the light is dim or the print is tiny. I gave in and bought varifocal specs, and to my amazement, I love them! They are a beautiful rimless mount, which I refer to as my ‘facial jewellery’, the vision is fabulous, and if something is ridiculously small I can still take them off easily and revel in my myopia. This means they are a tough act for multifocal contact lenses to follow, and I began to understand why some of my patients were dissatisfied with multifocal contact lenses in comparison.
So, I have found my perfect solution (Other than reversing the ageing process, which would clearly win hands down!). It’s what my Dad used to call the right tool for the job, and it goes like this…
My multifocal contact lenses mean I am fine without glasses for the most part, and that is my preferred option. I can read a menu (as long as the print is reasonable and the restaurant has more than one candle), and I can go shopping and read prices, as most shops are brightly lit. I can work comfortably at my laptop, and I prefer driving in lenses as my peripheral view is better, and it’s easy to pop my sunglasses on when necessary. In dim light or for very fine print, or threading a needle, I occasionally put a pair of readers over the top, and this is fine, as I don’t need to resort to this very often. If I’m spending a relaxed evening in low light, for example in the cinema, I prefer my glasses as the vision is clearer under those circumstances.
The first major thing I have learned is that one single solution is unlikely to work for a patient throughout their presbyopic life, and as practitioners we need to recognise when to offer something different. I’m much more understanding of the exasperation of losing near vision, and I now have a ‘portfolio’ of options to offer my patients, rather than an expectation that one optical appliance with magically solve the whole issue of presbyopia. I’ve discovered that moving from one multifocal to another ALWAYS requires starting again from the appropriate fitting guide, as the designs will be different, even if you’re sticking with the same manufacturer. Different materials (eg. going from monthly to daily) will fit and drape differently, so the results may vary. I cannot stress the importance of fitting guides enough!
I’ve discovered that presbyopes might need gently reminding that things ain’t what they used to be, that the latest design of sporty footwear won’t help them to run as fast as they did aged 20, but will make their current exercise regime more comfortable and achievable. The same goes for eyecare. Modern multifocals are brilliant, and will give a very good range of vision (including intermediate, unlike monovision!), but what they can’t do is take a presbyope’s eyes back to age 20. Having said that, what they will do is enable us presbyopes to almost have our youthful vision back. We can read something at eye level without having to tip our heads back (as with varifocal specs!), which is something we could do 20 years ago, so while in the supermarket reading prices on higher shelves we can blithely deny our age. We can read things at a normal working distance instead of at arm’s length, reducing the need to apologise in theatres when we have thrust the programme out in front of us, casually inflicting a minor head injury on the person sitting on the next row. We can sit in the sunshine reading a book with sunglasses on. There are so many tiny ways in which multifocal contact lenses help a presbyope to retain what has always been ‘normal’ until now.
The thing is, presbyopia tends to be thought of as a middle aged person’s problem, but I’m not ready to be middle aged yet. I want to preserve the myth for as long as possible, and I don’t think I’m the only one!
Traditionally, the process for multifocal lens design was long and laborious, limiting the number of designs which could be explored. The design team would simulate a new lens design on to an ‘average eye’ computer model, and this new lens would then be tested in clinic. The results would be consolidated, changes would be made to the design, and the whole process would start again.
In order to shorten this process and therefore allow more design options to be considered, Bausch + Lomb analysed multiple vision related variables, including refraction, higher order aberrations, corneal curvature, pupil size and axial length. They also measured residual accommodation across 9 distances, from 25cm to 6m^3^. This produced a system to conduct many virtual clinical trials, evaluating optic variables such as the width of the near and intermediate zones, the add power, and the change of power within a zone.
This has resulted in the 3-zone progressive design across Bausch + Lomb’s range of multifocal lenses, providing an excellent range of vision, especially in the intermediate zone, so necessary in today’s screen-centric world.
For those who persist in believing that presbyopes are unhappy with the vision provided by multifocal lenses, I invite you to consider your dentist. A study of dentists in the USA^2^ showed that more than a quarter of them failed to achieve the recommended near visual acuity for their occupation, and of those that failed at 35, 93.5% were over the age of 45. Personally, I like my dentist to see clearly – and I know lighting isn’t an issue for him at work! This study does suggest that there may be a large proportion of presbyopes ‘managing’ badly with near vision, presumably not reporting this to their optician or something would have been done about it.
Finally, there will always be those patients who demand even better vision than modern soft lenses can give – and this is why we have gas permeable lenses!
A range of training sessions, including some on fitting multifocals, are available through Bausch + Lomb for those who wish to improve their fitting skills further. Contact your local Territory Business Manager for details.
1. Rueff, Erin M.; Varghese, Robin Joy; Brack, Taylor M.; Downard, Danica E.; Bailey, Melissa D. A Survey of Presbyopic Contact Lens Wearers in a University Setting Optometry & Vision Science: August 2016 - Volume 93 - Issue 8 - p 848–854
2.Burton, JF, Bridgman GF ‘Presbyopia and the Dentist: The effect of age on clinical vision’ International Dental Journal 1990, 40(5):303-312
3. Kingston AC, Cox IG. Predicting through-focus visual acuity with the eye's natural aberrations. Optom Vis Sci. 2013 Oct;90(10). Available at: https://www.ncbi.nlm.nih.gov/pubmed/24013796
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