5 Reasons you might need more than one eyetest

1.  Eyetests are subjective

I wear size 9 shoes.  Every day of the week and any time of the day - always size 9's!  They might feel a bit tight at the end of the day but always size 9's.

"So what?" I hear you ask........

When we test your eyes we measure to a very fine tolerance and the four main elements of a prescription (sphere, cylinder, axis and add) can each be adjusted up and down in the tiniest of steps.  The result relies of our skill and experience and your responses to questions like "Is it better with one or two?" or "Is it sharper on red or green?".  These questions help us decide which tiny step to choose in each of those 4 main elements of the prescription but you may have noticed how difficult the question appears to be to answer correctly sometimes?  That's because we are not asking you to choose between a size 8 or 9 or 10 shoe - we know you are a size 9 by this point but are trying to decide if you are an 8.9, a 9.0 or a 9.1 - difficult decision to call!

If you multiply those 4 main elements of choice out you can easily get to 81 correct answers for someone's prescription.  If you go to 10 opticians today for an eyetest, you may well get 10 different 'correct' prescriptions!

Once we have completed a subjective result we then try and test it further based on environment.

2.  Your environment

We can refine your prescription based on your visual demands in your world.  Do you drive?, Do you read? If you do read, is it books, newspapers, tech devices?, Do you have specific hobbies that require vision correction?  How far is your TV from your sofa? etc.

If we understand what your real life is like we can make better judgements on the prescription that best suits those needs.  

Before your next appointment, have a think about what areas of your life you have the most visual challenges so that we can maximise how we can help you.

3.  Your general health and wellbeing

Illnesses can affect your prescription results.  Your eyes have focussing muscles and just like the rest of the body they get tired too.  Even a common cold will affect your ability to focus.  Do please let us know if you are poorly so that we can best support you visually.

Often it might not be the illness but the medication you are taking.  Anti-histamines, pain killers and HRT drugs all might have an affect and there are many more simple over the counter drugs that can affect vision.  Complex therapy drugs will have big affects so please always let us know what medications you might be taking and we can advise you accordingly.

4.  Managing your expectations

Our role is to ensure your spectacles allow your eyes to be in focus at one distance or multiple distances.  The more complicated they need to be, the more compromises that introduces to the final pair of specs.  A progressive lens (used to be called varifocals) has bespoke designed areas on the lens for different working distances - they work well in regular head positions but a plumber trying to look at something close under a sink might not easily be able to get into a position where the reading area is useable! 

We test your eyes through the centre of very small test lenses that can give a very different feel to when your spectacles are made over a much larger lens.  'Full sized' lenses have various aberrations such as Chromatic Aberration, Oblique Astigmatism and Spherical Aberration that are not noticeable on the smaller 'test' lenses.  These are exaggerated by more complex progressive lenses too!

We'll talk you through the various lens options and explain where compromises might be needed to adapt to your new glasses.

5.  Time

To ensure we get things right for you, we promise to give you at least 30 minutes with your optometrist and more if necessary.  Our Vision Experts will give you as much time as you need to explain your spectacle lens options, choose the best frame for you and take all the frame and lens measurements using the very latest technology.  All this together allows us to provide you with the very best eyewear to suit your needs.

All we ask is that you give your new spectacles and your eyes the time to adapt to each other.  You'll be seeing things slightly differently and it does take time to adapt to how you see.  If you give your brain the time to do this you will reap the rewards.

Still have questions or concerns?  Even if you got your spectacles elsewhere, feel free to drop us a short email and our Vision Experts will try and help.