Causes of Astigmatism

Find out the causes of astigmatism and what corrective procedures are available.

Most people are born with astigmatism, inherited in their gene pool, but it is also possible to become astigmatic after an eye injury which scars the surface of the eye, the cornea.

Some people also suffer astigmatism as a result of eye surgery or it can develop when the cornea becomes thin due to getting an eye disease called keratoconus.

It affects a large percentage of the population although many don't know they have it as it may be mild and does not need correcting.

Let's find out the causes of astigmatism.

What is Astigmatism?

Astigmatism causes blurred vision due to an irregularly shaped cornea where it has an oblong, oval shape rather than a spherical shape.

Most sufferers have what is known as regular astigmatism where the curves of the oval shape are exactly 90 degrees apart. If they are not, things get a bit more complex and this type of severe astigmatism can be harder to correct, limiting the options available.

Add to this the accompanying factors of being short or long-sighted, and some eye prescriptions can read like a telephone directory!

A toric lenses prescription has 3 numbers on it - Power to correct short- or long-sight; CYL to denote the angle (cylinder) and degree of astigmatism; Axis to show the positioning of your astigmatism correction.

Contact Lenses for Astigmatism

Many people don't know that they can wear contact lenses for astigmatism. My brother suffers from severe astigmatism and tried to wear hard contact lenses when he was a teenager (30 years ago!) to go night clubbing. Sadly they didn't work and aside from not being able to see the best looking girls, he also suffered from eye strain.

But technology has moved on and today, people with astigmatism can wear both rigid RGP lenses AND soft contact lenses, known as toric lenses. They are even available as daily disposable options, not to mention colored and bifocal options.

The severity of your astigmatism will determine which type of lens is best for you so it's important to visit an eye doctor with specific experience of fitting toric contact lenses for astigmatism. While many people can happily wear soft toric contacts, people with severe astigmatism may not have full clarity of vision as soft lenses rotate in the eye more readily and for a toric lense to work efficiently, it must stay in one position on the eye.

Toric lenses are more expensive as they have 2 different powers, one to correct astigmatism and the other to correct either myopia or presbyopia; fitting them takes more time too.

Lasik Surgery for Astigmatism

If contact lenses are either not available for your prescription or do not correct your astigmatism properly, you can revert to eye glasses OR take the plunge and opt for LASIK surgery.

LASIK stands for Laser-assisted in-situ keratomileusis, a real mouthful to describe what I can only call a very scary procedure where a doctor cuts into the cornea on the surface of the eye, lifts a small flap and then reshapes the curvature of the cornea into the right spherical shape.

If you're brave enough to put your delicate eyes under a laser beam then wearing glasses and/or contacts can be a thing of the past, but beware if you play a lot of sports or do work outside where things can easily get into your eyes. Once the surgery is done, the cornea is weakened, making your eye far more vulnerable to damage in the event of an accident.

Now you know the causes of astigmatism, read our related articles below for how to get lenses to correct it.

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