Astigmatism an Easily Solved Problem
5 min Oct. 22, 2021
The first thing to say about Astigmatism is that there’s nothing to worry about. Astigmatism is very common and highly unlikely to be anything other than an eye condition with easily available solutions.
So don’t waste time getting anxious if your optometrist tells you that you’re astigmatic. A solution is just around the corner!
WHAT CAUSES ASTIGMATISM?
Before looking at options designed to correct astigmatism, you may want to know more about what causes the condition.If you are astigmatic, the chances are it is because your cornea is not a perfect spherical (football-shaped) curve. The cornea is the transparent part of the eye in front of the coloured iris containing your pupil. It acts like a first lens, bending light rays before they reach the actual lens in your eye - and finally the back of the eye (your retina).
Normally the front of the cornea is a perfect sphere. With astigmatism, it is more like a rugby ball. This makes the optics a bit more complicated. If the lens inside your eye (behind the cornea) is also not perfect in shape, it can add to the astigmatic effect or reduce it.
If the cornea shape resembles a rugby ball, you have ‘regular’ astigmatism, but if there are additional uneven curves with variable steepness, you have ‘irregular’ astigmatism. Either condition can combine with general short sightedness or long sightedness, as well as presbyopia later in life. Sometimes mild astigmatism is hardly noticeable. However, the more pronounced it is, the more you need corrective lenses to help you focus better.
HOW DOES ASTIGMATISM CAUSE BLURRED VISION?
So, what goes wrong, causing all this fuzziness?
With perfect vision, light rays entering your eye focus at a single point (like sunlight when using a magnifying glass) on your retina - the ‘screen’ at the back of your eye. This gives the retina one clear image, like a sharply-focused film projection at the cinema.
With astigmatism, the eye creates more than one focal point, projecting somewhat blurred or distorted images onto the retina. This sends multiple images to the brain, so instead of a clear picture you get a lack of focus.
You may perceive this as a general haze, or through small differences in how sharp or straight horizontal and vertical lines appear in a building, tree or indeed any structure. The effect is more pronounced when driving at night.
All of this explains why astigmatism was defined by its discoverer the Rev. William Whewell simply as “a defect in the structure of the eye whereby the rays of light do not converge to a point upon the retina." This was way back in 1849, with the term combining the Greek for ‘without’ (the ‘a’ at the front of the word) and ‘stigmatos’ meaning a mark, spot or puncture.
ENOUGH OF THE HISTORY. TELL US ABOUT THE EFFECTS.
Well, even a minor case of blurred sight can cause headaches and eye strain, as your brain tries to make sense of what you are looking at.
You may also feel tired, irritated eyes and struggle to see clearly. As noted, this is especially likely when driving at night. That’s because astigmatism can turn light sources into flares and glare, surrounded by starburst haloes. It’s like fireworks night, just less exciting and more dangerous!
WHERE ASTIGMATISM COMES FROM?
Most people with astigmatism are born with it, though it can develop in later life. Like many eye conditions, it may be an unwanted inherited gift from mum and dad: if your parents have it, you’re more likely to have it too. In some cases though, it can be a result of trauma or other problems with your eye changing the shape of your cornea.
Rubbing your eyes is not going to cause astigmatism - or make it worse - and a very light massaging of the eyelids is a good thing. Anything more rigorous is best avoided: your eyes are delicate so should be treated with care!
SO, WHAT DO I DO ABOUT THE CONDITION?
Let’s assume you do indeed have astigmatic eyes. The condition will not disappear on its own, but sorting it out is fairly straightforward. See your optometrist, get your vision checked, then choose your correction solution: contact lenses, glasses or refractive (LASIK / LASEK) surgery.
This is where the word ‘toric’ becomes important to our story. A torus is basically a tubular ring, like a donut. Imagine a thin vertical slice of that donut’s ring. That’s the shape of the ‘toric’ part of a contact lens.
Since it has different powers to bend light at different points of the lens shape, a toric lens refocuses the rays coming into your eye, ensuring that they meet at a single point on your retina.
SO THE CONTACT LENS SOLUTION I NEED IS...
A toric contact lens! These days, contact lenses are arguably one of the best and easiest way to correct astigmatism. A toric contact lens keeps doing its great work all day long. With a huge range of lens types, materials, fitting shapes, powers and designs, there are toric lenses for almost every type of astigmatic correction and personal preference, including daily disposables and monthlies.
You can add the convenience and hygiene of daily disposable lenses to the secure and stable fit of a toric lens by using DAILIES® AquaComfort PLUS® Toric contact lenses. Alternatively, you and your optometrist may decide to choose AIR OPTIX®® for Astigmatism, combining comfort and clear sight in a monthlies format. Made from silicone hydrogel, these toric contacts not only correct your vision, they also let more oxygen reach your cornea.
Science has moved on in leaps and bounds, ensuring no one with astigmatism should ever be denied their choice of contact lens.
So, whatever your preference, if you’re seeing vertical or horizontal blurred lines, often getting headaches or suffering from poor night vision, a visit to your optometrist to explore contact lenses for astigmatism is a very good idea. It could make ‘toric’ your favourite new word!
References: 1. https://www.webmd.com/eye-health/astigmatism-eyes. Assessed: 10/03/2021