Eye Astigmatism Explained


So You’ve had your eyes examined and you got
your glasses prescription, which looks a little bit like this, but what happens if
you’ve been told that you’ve got astigmatism and your prescription looks
more like this? If you’ve never had astigmatism explained to you or you’re
still confused… then in this video I’m gonna make sure that astigmatism explained in a way that makes sense. I’m Martin Oguzie and this is Martin’s Eye Tips, thank you for joining me. On this channel we’re all about bringing you eye care tips, how-to videos and product reviews all designed to help you see better, more
comfortably and to be less anxious about your eyes so if that sounds interesting
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that notifications bell so you get notified every time I release a new
video. So let’s get started with today’s video which is all about astigmatism. So
in this video; in order for astigmatism to be explained we’re going to talk
about three key areas, first of all what is astigmatism, secondly how does astigmatism affect your vision and thirdly how we prescribe for astigmatism.
So I want to start today with my a Peace Of Mind Point and that is to say that my
astigmatism is not a disease and, that’s an important thing for you to beware of
because often I see people when they’re first introduced of term astigmatism
they concern whether it is a condition that has sight threatening implications
or whether it means that there’s something more serious going on with
their sight and with their vision an actual fact it’s a very common condition
and a cause for us to say that most people have some degree of astigmatism
it’s my experience more unusual to find somebody who has just a completely
spherical eye and prescription with no astigmatism whatsoever so it’s
definitely not a disease and definitely not something you have to panic about so
what is astigmatism now to explain that I’m going to be referring at point to a
glasses prescription report so if at any point you want to understand a bit more
about how your glasses prescription works then please refer to the link up
there and that will take you to a video that I
made previously my stigmatism is much like nearsightedness and farsightedness
in that it’s an error in the curvature of the front of your eye the cornea
which means that the cornea which is that first surface on your eye that your
breast the contact lens on it now has two different curvatures a steeper
curvature and a flatter curvature compared to an eye that doesn’t have a
stigmatism where all the curvatures are of equal power so rather than being a
spherical in shape like half of a beach ball might be instead because of this
difference in curvature at the front of the eye on the cornea then the eye has
more of a shape like a rugby ball unless basically astigmatism explained in its
simplest form the result of this difference in curvature in two
directions is that your eye instead of having one a uniform focus point at the
back of the eye it now has two focus points at the back of the eye now
because in astigmatism we have these two different focus points this is what
causes the problems in vision that we associate with astigmatism now it’s also
worth mentioning that you can get farsightedness and astigmatism in
combination as well as nearsightedness and astigmatism in combination or you
can get astigmatism on its own as well so how does astigmatism affect
your vision now many people say that it can cause blurriness of your vision but
in actual fact the key thing with astigmatism is that it causes distortion
and this distortion comes about because of these two focus points that you have
and the further away they are the bigger astigmatism is and the more distorted
things will look to you as well so on the keyways astigmatism affects your
vision is that it distorts straight lines and this can make texts quite
difficult to see so if you’re trying to do read a number plate or if you are
doing intricate reading in bed for example then it could make it difficult
to tell one letter from another based on where your astigmatism lines up with the
lines on the letters so this can cause that confusion have between letters so
other than things just look in blurry astigmatism can bring about distortion which can make fine detail more difficult. So how do we prescribe lenses
for astigmatism so the best way to explain this is by having a look at a
copy of somebody’s prescription so that I would know astigmatism would only
require one power that is the same in all directions on the curvature of the
eye on the cornea and that’s why when you look at your prescription you’d have
a prescription that looks something like this with simply one number in the
sphere box and that number then could be a plus or minus depending on whether
you’re far or near sighted the sill and the axis boxes would then remain empty
now the eye with astigmatism requires more information and more detail in
order to achieve the right lenses to correct the vision and bring best
clarity and sharpness and that’s why when we have a look at the prescription
of somebody with the stigmatism we now require information in the sill box
which stands for cylinder and the axis and these two numbers go hand-in-hand
you can think of the cylinder number as a power or a strength of your
astigmatism where as the axis is a measurement in degrees to inform us
about where we want to put that curvature difference so when we correct
astigmatism we need to add the additional power called the cylinder
power or the sill on top of any sphere that we might have now so we don’t end
up having a combined power of the sphere and the cylinder that is correcting
equal strength in all directions who wouldn’t actually deal with the
curvature difference we then need an axis the cylinder has an axis which is a
direction along which there is zero cylinder power so that when we combine
this cylinder and a sphere then along the zero power only the power of the
sphere comes through that way we’ve got a lens that now has the cylinder power
in one direction only and also the combination of whatever’s in the
cylinder and in the sphere in the other direction and that’s how we deal with a
stigmatism now every eye is different and as a result where the axis needs to
be on your eye is different it’s never always in the same place for everybody
so for some people it may be at 90 degrees others it may be along
and in fact it could be any number between 0 and 180 degrees
now glasses aren’t the only way to be able to correct astigmatism of course
you’ve also got the option of contact lenses and we have specially made
contact lenses that deal with the curvature differences on the eye as well
and these lenses are called Turkic contact lenses so laser correction is
also another option for people with astigmatism so it doesn’t rule you out
too like you used to back in the early days of laser so in fact you can
actually get quite high levels of astigmatism corrected with a laser
correction now so and I think powers up to about six diopters can be a corrected
and that’s pretty high given that most people will be comfortably under about
four so that’s essentially the key things that you should know about
astigmatism so for my tip of the day if you’re somebody who doesn’t know whether
you’ve got astigmatism but you’ve got a copy of your prescription then I suggest
you pull that out and have a look at that prescription because that will tell
you whether you have a stigmatism or not so have a look for a number in the SIL
box and a number in the axis as well so if you have numbers in those two boxes
then yes you have astigmatism if it’s a small amount of astigmatism
it may be 0.25 minus 0.25 sometimes it can be plus as well if it’s a large
amount of astigmatism then it will be a number significantly higher than that
today’s question for you is do you have astigmatism and if you do what strength
is it leave me a message in the comment section below let me know what strength
your astigmatism is and that might be a number that is a minus 1 – 2 – 3 whatever it
may be, leave a message down there and I’ll have
a look at that if you want to know more about your glasses prescription then
please check out my video over here and if you want to find out more about
whether you need glasses or not then please have a look at the playlist
listed over here as well until my next video take care

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