Posts Tagged ‘astigmatism’

I Heard a Rumour

Sunday, August 7th, 2011

After a hectic week in practice, chatting to patients face to face instead of online conversations, I’ve again been faced with some universal questions that crop up very regularly. They’re perhaps not the kind of query that you’d ask your optician about, more the sort of untrue-truth that everyone seems to believe. So let’s try some myth busting and dispel these rumours once and for all……..

I know that if I have an eye test I’ll get the answers wrong, and end up with glasses….. Just because the optician is asking for a response from you, it doesn’t mean your eyesight will depend on your replies for ever after! Several parts of the test give your final lens power, and they will re-check again and again, with tiny differences in the options to refine and perfect your prescription. They will know if one answer is a bit off kilter!

I’ve got an astigmatism, so I can’t wear contact lenses……..An astigmatism is a common eye defect that means your eyeball is shaped more like a rugby ball than a football, and your lens prescription has one power to correct the long axis of the rugby ball, and one for the short. We can do this with specs or contact lenses, and nowadays it’s rare for anyone not to be able to wear contact lenses, at least for some of the time.

I need help for reading, so I’m long sighted…..Before age forty, eye defects fall into the categories of long or short sightedness, possibly with an astigmatism too. If you’re long sighted vision is tricky at all distances, if you’re short sighted you can see close too but not far away. After age forty your eyes lose the ability to focus close too, regardless of your general prescription. This is called presbyopia. So you need correction for your long or short sightedness, and the presbyopia. This usually involves varifocals, bifocals or specs for reading and distance.

If I wear glasses my eyes will get weaker……..Your eye defect, whether long sighted, short sighted or astigmatic are caused by the shape and curve of the eyeball and some of the structures that contribute to your sight. You can’t change those factors, whatever you do. Glasses will just make you used to seeing clearly, so you’ll feel more comfortable with them on. We can’t perform the miracle of changing your sight!!

Varifocal Glasses

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The Stigma of Astigmatism!

Monday, February 14th, 2011


We still get confused patients mailing us with queries about this weird eye defect they have: “I’ve got a stigma in my eye!” Or even a stigmata! Or sometimes an astigmatism……clearly there’s still some confusion about this tricky little eye problem, so here are our ten facts about astigmatism, for those of you worried about your stigma!!

1.Astigmatism is very common – most patients who need specs have some amount of it. It’s just another part of your prescription, and nothing at all to worry about.

2.It simply means that instead of being spherical like a football, your eye is shaped more like a rugby ball. So you need one correction for the long axis of your rugby ball, and one for the short axis. Your spectacle lens has the two powers built into the lens.

3.As each astigmatism is at a varying angle, your spectacle lens needs to be precisely placed to correct your sight. So if you damage your glasses and the lens is moved out of alignment, your optician will need to put it back into place.

4.You can have glasses or contact lenses to perfect your sight, so don’t worry that the astigmatism means you can’t have contacts. Some amount of it can be masked by standard contacts, for higher amounts of astigmatism you need more specialist lenses. They will be weighted or cut across the bottom to make sure orientate in the right way.

5.If your astigmatism is high then one edge of your spectacle lenses will be thicker than the other, Take your optician’s advice about suitable frames to help to disguise this.

6.As with your amount of long or short sightedness, your astigmatism can vary. Small variations are nothing to be concerned about.

7.Changes to your astigmatism can make your new specs feel a bit strange. Plates might look oval, shelves might slope……but it wears off quite quickly and the only way to get used to it is to stick your glasses on and try to ignore it! After a day or two it will settle down!

8.Even if you’re not very short or long sighted, but have a high amount of astigmatism, then you might need to invest in thinned down lenses. It will reduce the thickness and weight, and the specs will look better.

9.Your Optician will tell you if you have an astigmatism, and don’t be afraid to ask questions! He can tell you how high it is and what you specifically need to aware of.

10.Unless your astigmatism is very high, you won’t see the correction within your glasses. If it is high, you might see that the lens looks a little distorted across one axis as you look at it. In wear you can’t see it, and hopefully the only way you’ll know is thanks to your perfect, corrected vision!

Varifocal Glasses

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No Stigma

Friday, May 28th, 2010

When opticians hand out prescriptions to patients, or tell them about any visual defects, patients can be confused about words used or explanations that are not clear enough. One repeat question is on the subject of Astigmatism – I’ve got a stigma we’re often told! So let’s clear this up once and for all….

An Astigmatism is nothing to worry about, is very common, and can fluctuate along with your amount of long or short sightedness. It may cause headaches and your vision will probably be blurred if it’s not corrected by glasses or contact lenses. Most people have some amount of Astigmatism, they’re either born with it or it develops over time.

It simply means that your eye is shaped more like a Rugby ball then a football. Look at a football and of course you’ll see that the curve is the same all over the surface. With a Rugby ball there are different curves for the long and the short diameters of the ball. An Astigmatic eye is like this, and the defect lies either in the Cornea or the lens inside your eye. The eye can’t focus incoming light where it’s supposed to, as two different images are produced, from the two curves of the Rugby ball.

Your sight can be corrected with glasses or contact lenses. The lens has to be held at the correct angle, as everyone’s Rugby ball is at a different orientation. Contact lenses for Astigmatism are weighted or have the bottom chopped off to hold them in place, spec lenses are simply cut and placed at the right angle. Along with the Astigmatism you’ll most likely be long or short sighted, this is the Sph part of your written prescription. The Cyl part of your prescription deals with the Astigmatism, and the Axis part is the angle at which your lens must be set.

When your Astigmatism is corrected for the first time, your vision might seem a little strange, because you’ve been used to coping without help. You might even feel a bit sea-sick for a day or two! It wears off quickly as your eyes adjust, and vision is usually much more comfortable with the right lenses in place. So don’t worry – there’s really no stigma attached to it!

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Optimum Position

Wednesday, February 17th, 2010

When a patient has a problem with their glasses it seems an obvious answer is to query the strength of the lenses. Sometimes of course the prescription has been read wrongly, or sight may have fluctuated, but more often than not the glasses are correct and so was the examination. So what else may be wrong?

The positioning of the lenses in your frames is as crucial as the correct power. If you have an astigmatism then the lens has to sit at the given angle – the axis – on your prescription. The higher your cyl or astigmatism strength the more crucial this angle is. You’ll feel seasick and suffer distorted vision if the axis is wrong. This was a dreadful problem when frames were round as the lens would swivel at will within the frame!

If you sit on your frame or manage to distort it in some other way, then you may inadvertently change the orientation of your lenses, so get them straightened before you give yourself headaches and eye strain. Return them to your online optician or go back to your high street optician and get them adjusted. If returning them to the online optician make sure they have a copy of your prescription so that the axis definitely in the right place.

The distance of your frame from your eye can also be an issue if you have a high prescription. This measurement is snappily called the back vertex distance, and is the space, measured in millimetres, from your eye to the back of your spectacle lens. Wearing glasses too far down your nose can be as detrimental to your sight as wearing the wrong power, so if you feel the power of wrong then talk to your optician. Here at the Internet Glasses Companywe advise clients if this will be an issue for them and discuss fitting options.

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A Warped Point of View!

Friday, November 27th, 2009

I’ve always been a bit short sighted, and then when I had an eye test last month the optician said I now have an astigmatism – help – I thought! I’m falling apart, or is that just me being a bit melodramatic?! So I asked a few questions, got my specs, and now it’s whole new world, and it’s a bit weird…

If I’ve got this right, astigmatism just means that my eye is a slightly different shape to normal, rather like the rest of me! Instead of being a sphere shape, that is totally round like a ball, mine is elongated one way, like a rugby ball shape. (The optician said ellipse but I needed it plainer than that!) When the eye is round you need the same prescription all over your glasses to make you see clearly. When it’s got an astigmatism you need one strength for the long diameter, and one for the shorter one, and they cleverly build this into your glasses lenses. The optician told me that the lenses always have to placed at the correct angle, as the specifications are very exact, they have to have the two different powers as well as being set at the proper angle. So no more sitting on my frames and bending them back myself!

Astigmatism shown in cross section

Astigmatism shown in cross section

When I got my glasses, they looked just like the last pair; this special astigmatism bit can’t be seen. I could really see it when I got them on! My shelves were going down to the side, and my computer screen looked like a cartoon shape. After a few hours wear I actually felt like I was on a boat in very bad weather. I rang the optician, who said that this is normal, it’s just my eye learning to accept the help that the lens is giving me. Sure enough, it did wear off after three days, and I no longer feel drunk!

Apparently the astigmatism can come and go, and mine isn’t much, so I may not have it another time. As its low my contact lenses won’t need it built in, so the few pairs of day wear lenses I keep for football will be ok. I’m glad I asked lots of questions when I got tested, I’ve stopped fretting now!

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Any questions?

Wednesday, August 26th, 2009

The experience of having your eyes tested – secluded in a darkened room with a healthcare professional, glasses taken away from you, impending costs – can render the strongest amongst us a little dazed and confused. Even if you buy glasses online, you do however have to keep your spectacle prescription up to date, and it’s also important to get your eye health checked. So here are some answers to a few of the questions you may have liked to ask….

What on earth is an astigmatism?!! Opticians throw this word around, but patients often don’t really understand what this means. Astigmatism is just another part of your prescription – nothing sinister, nothing to worry about – it just means that your eye is shaped more like a rugby ball than a football. You need one power in your glasses to correct the long axis of the rugby ball, and one to correct the short. It may vary through your life, it may come and go. Without your glasses on what you see will be a stretched image in one direction.

Will wearing glasses make my eyes weaker? No, long term wearing or not wearing your glasses will not alter your sight. You just get used to seeing clearly with them on! You’ll also get a headache  if you strain to see something without them.

Do varifocals have to go in big frames? No – nowadays they can be fitted into even quite shallow frames. No optician will make them up for you if the depth is not sufficient.


Does using a VDU damage your eyes? No research has proven this, but be aware of a few simple rules. Blink often and give your eyes a rest by looking away from the screen at regular intervals. Wear your glasses if you’re been prescribed them for computer distance. An anti-reflection layer added to your lenses will reduce uncomfortable glare.

My prescription is high, why do my lenses always have to be so heavy? The thickness and therefore the weight of a spectacle lens is governed by the power, so higher prescriptions will always be heavier. You can reduce the thickness by choosing a thinned down lens, and a small frame. A plastic frame will spread the weight evenly across your nose.

Any other questions? Contact your optician, even if it’s after the event. Watch this space or mail the IGC, we’re always happy to help.

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All Greek To Me

Monday, July 13th, 2009

Sitting in the optician’s chair, bedazzled by the bright lights and blind without your glasses on, having an eye test can be a confusing experience. After the exam, the optician gives you your prescription – the power you need for corrective specs. So do you understand it? Read on for some simple explanations of what the numbers mean.

The first part says sph or sphere, and this tells you whether you are long sighted – it has a plus sign, or short sighted – it has a minus sign. It increases in steps of 0.25, and the higher the number, the stronger your lenses. If this says plano, or has the Greek symbol alpha in it, then you have no power here.

If the cyl or cylinder bit is filled in, you have an astigmatism. This is a common eye defect, and simply means that your eye is shaped more like a rugby ball than a football. Axis tells us which angle the cyl power needs to oriented to.

If you have any prism power, this corrects double vision. This may make your lenses a little thicker. The higher that any of the powers – sph, cyl, or prism are – then the stronger, and therefore thicker your lens will be.

If you need help for close work, then the reading section will be filled in, or will have a single power written across it – something like Add +1.50. This tells us what we need to add to your distance power to help you to see for reading.

Some opticians also write down your VA or visual acuity, this is how well you can see. It looks like a fraction. If it says 6/6 you have prefect vision, so well done you!

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