If you have never worn Contact Lenses, are a lapsed or a current wearer – we want first of all, to start this article with a confession! We love the science of Contact Lenses and Contact Lens Practice! We also know that 99% of Contact Lens wearers love them too! Even people who fall out of love (with other people) hope they will find that special one, it’s much the same with Contact Lenses – somewhere out there is a special lens for you. If you haven’t found it yet, we as your local Contact Lens Practitioners can help you find it.
Having started with the emotional aspect, let’s move on to what will most interest you – the huge and growing range of Contact Lens options for you as a potential, lapsed or current lens wearer. In this article we will give you a synopsis of what the options are, however their complete applications for each fill volumes of text books, not to say more than a few years of education, training and experience.
We thought discussing the materials they are made of is a good place to start – while not wanting to delve into the delights of polymer chemistry! Nowadays the Contact Lens world is divided into two main family branches –
Branch one - Rigid Gas Permeable (RGP) lenses succeeded the old (non-permeable) hard lenses. The modern equivalent still has a definitive shape of its own (which can be an advantage) but crucially allows oxygen to transmit though it. Typically RGP lenses are around 8.00mm – 10.50mm in diameter, however there are also larger forms, called sclerals or semi-sclerals. As well as giving crisp vision, another specialist application for a specialist definitive rigid shape is to temporarily mould the cornea over-night to enable patients not to require glasses or Contact Lenses though their waking hours – this technique is called Ortho-Keratology (Ortho-K) you can read more about this in a specific article http://www.eyedropsdatabase.co.uk/patients/guest-articles/orthokeratology
Branch two - soft lenses - these have a shape but you can, and patient’s occasionally do, turn them inside out, they contain liquid (but not water!), they look and feel gel-like – they are even called Hydrogels.
As in all family trees there is the possibility of in-breeding, however in the case of Contact Lenses this is not necessarily a bad thing! – Hybrid lenses have a rigid centre and a soft skirt.
However the largest branch of the family tree contains the soft lenses, they have the characteristics of having many different water contents (this is widely used but poor terminology, they do not contain, nor do we want, water in them which can be a source of severe infection) and oxygen transmissions, the two need not be linked.
Over 15 years ago silicon was added to soft lens materials, this increased oxygen transmission to the eye – good – a step forward. However all self-respecting Contact Lens Practitioners will not confine themselves exclusively prescribing one or another. Hydrogels or Silicon-Hydrogels both have a place in modern Contact Lens practice.
Now soft lenses, be they Hydrogels or Silicon-Hydrogels have families of their own, Daily Disposable – no cleaning, fresh lens each day. Two weekly/monthly Disposable – normally cleaning and disinfecting with a single bottle, so different processes, but only one bottle of solution. Then lenses discarded at the end of each prescribed period.
Toric lenses – lenses with prescriptions that correct astigmatism, which most of us have to a degree, just like spectacles. The old adage – “you have rugby ball shaped eyes so you can’t wear Contact Lenses” - should not be heard in the 21st century!
Multi-Focal lenses – lenses with prescriptions that correct presbyopia, which all of us have if we are over 45, just like spectacles. The old adage – “you need bifocals so you can’t wear Contact Lenses” - should not be heard in the 21st century!
Extended Wear lenses – lenses prescribed with a view to be worn 24 hours a day for a set number of days, convenient - certainly, practitioner care for you – high, possibility of adverse effects – higher than daily wear. As with all Contact Lenses, risks, benefits and options should be discussed, even more so with these.
One last, very new, Contact Lens application that is widely discussed, but fair to say not widely prescribed yet, is Myopia Control – the effect of slowing down the rate of increase in the prescription for a short-sighted (myopic) child. It is though that a combination of factors contribute to myopia in early childhood; family genes, amount of time spent outdoors, and peripheral blur (out of focus effects, not readily observable, in the periphery of vision) and perhaps others. One of the treatments understudy are special Contact Lenses that reduce the peripheral blur contribution and may reduce the progression of myopia.
Yes, there is a lot to love in Contact Lenses, if this article has whetted you appetite to know more do discuss this with your local Contact Lens Practitioner. Fall in love for the first time, fall in love again or stay in love with your Contact Lenses! In the same way there isn't a drug/medication that doesn't have a side-effect (noticeable or otherwise), there isn't a Contact Lens that doesn't interfere with the eye's tear film (noticable or otherwise), so using specific drops with Contact Lens wear is quite normal, and to a certain extent recommended. Do see specific advice from your Contact Lens Practitioner. See Dry Eye Drops article.
Remember Contact Lenses are legally medical devices, so should only be prescribed (or changes made to the prescription) by a suitably qualified registered (GOC or GMC) practitioner. Do not make changes yourself or allow other non-qualified people to make changes for you. If this article has whetted your interest to know more it is always best to consult your current ECP initially, perhaps using the Contact Lens Referral Directory resource if your practitioner is unable to help, refer you to someone else or indeed contact us.. Very recently we now have specific materials designed to enhance comfort throughout the day, these materials along with specialist tests that can identify ways to help Contact Lenses to be more comfortable, mean that even if you have failed with lens wear in the past you have every possibility of being successful now.
The importance of professional care - we have talked a lot about those small plastic discs that, rather like modern pharmaceuticals, can enhance life, but should be treated with respect, now what about the even more important aspect of professional care? Before having the lenses prescribed, and during the year's of contact lens wear, you will have had a general eye exam (sometimes referred to as a sight-test in old money), at least 2 yearly. As the name implies, this is not the same as your Contact Lens examinations, they may follow one another, or take place on separate days, they may take place in the same or different rooms, even by the same person or different people, but they are two distinct entities, rather like having a general health exam and a specific specialist exam. One more point to clarify, your spectacle prescription and Contact Lens prescriptions are again two different entities, and don't necessarily have to change in step with one another! Don't worry your practice understands all the nuances, for your practice visits just follow their advice on what to do and when, if in doubt ask them. Some visits you wear lenses, others you don't - if they don't make it clear each time - ask them to. Take your glasses and Contact Lens case to all your appointments, the special disclosing dye used to reveal cellular damage will stain lenses if you wear them again too soon.
All exams will cover your general health, medications/supplements, medical and eye history and if you've worn Contact Lenses before that important subject as well. In addition things that occupy your time and/or are important to you such as in front of a computer 8 hours a day, professional driver, Olympic swimmer, work with noxious fumes etc. etc.
Your eye's ocular surface will be microscopically (literally) examined and measured, lids turned and pressed (quite painless), tears analysed, then, and only then will, a Contact Lens be selected to assess you with, from the many options described above. If a reason is found not to prescribe lenses, or you need to improve your eye's health before the assessment you will be advised.
The on-eye lens assessment can range from a few minutes to a few hours, either in or outside the practice, lenses then may be prescribed. In actual fact the lenses, and your response to them, is constantly assessed as you wear them in the weeks, months and years to come. When prescribed you will be advised on your expectations, risks, benefits and options. You will be fully taught on care, handling, the do and the don't and asked to state you fully understand - if you don't - we want you to ask. This huge amount of 'TLC', provided by us to you, continues all through your years of wear, it is quite simply expert care, in all senses of those two words! Having read through all the above you may think 'continuity of care' is important, so that you see the same practitioner on each visit, if you do - please ask for a named person when your next appointment is made.
If this article has whetted your interest to know more it is always best to consult your current ECP initially, or you could Email Mr Andrew D Price FBDO(Hons)CL, COA:
Personal portfolios can be found here:
- Mr Andrew D Price FBDO(Hons)CL MBCLA
- Mrs Elizabeth Ralph FBDO CL MBCLA
- Mrs Vanessa Uden FBDO CL MBCLA
- Mr Ganeshbabu Mahalingam MPhil PhD FCOptom FBCLA ProfHigherGlaucoma
Andrew D. Price, for and on behalf of all Contact Lens Practitioner colleagues across the UK