What is astigmatism?

From the wide array of vision problems which affect humans, astigmatism is without the doubt the most misunderstood. Starting from the pronunciation of the condition (people tend to say “a stigmatism” – which is obviously incorrect) and moving on to its diagnosis and treatment, astigmatism surely needs better understanding among the general population.

What is astigmatism and what are its symptoms?

To start off, astigmatism is a refractive eye error, just like nearsightedness or farsightedness. To further define the condition, this means that is it not a health issue or an eye health problem – it just means that the eye has trouble with focusing light. The physical phenomenon is that multiple focus points appear in the eye, both in front of the retina and behind in, instead of the one (normal) focus point. Due to the fact that astigmatism is characterized by multiple focus points, symptoms include blurry vision at all distances, which is normally correlated with headaches and frequent squinting.


What causes astigmatism?

Since astigmatism is a physical eye defect, it is usually caused by physical defects of eye components, like an irregular cornea. For example, a normal human cornea has a round shape, just like a ball. If it is affected by astigmatism, it will look more like an oval, with one line significantly longer and more curved than the other one. Another cause of astigmatism is an unusual shape of the lens inside the eye – in this case, the condition is called lenticular astigmatism.

What are the types of astigmatism?

Astigmatism is categorized into three main types:

– Myopic astigmatism. This type of condition appears if one or both of the eye’s meridians are nearsighted. In case both are nearsighted, astigmatism only appears if they have a different degree of nearsightedness.

– Hyperopic astigmatism. Same as above, except the meridians are now farsighted.

– Mixed astigmatism. This occurs when one meridian of the eye is nearsighted while the other is farsighted.

Also, astigmatism is categorized in regular astigmatism (when the two meridians of the eye are perpendicular on one another) and irregular astigmatism. The first category is a lot more common while the second is usually caused by physical eye injuries.

How common is astigmatism?

More often than not, astigmatism appears rather early in life, with most of its patients being children and teenagers. According to recent studies, roughly 28% of children suffer from astigmatism of a certain degree, while almost half of those people who wear glasses (47%) suffer from astigmatism in one eye or both eyes.

How to correct astigmatism?

Astigmatism can easily be detected during a regular eye exam. For the correction part, each patient has three options: glasses, contact lenses, and corrective eye surgery. Glasses and contact lenses are the most common treatment option. The difference between regular lenses and lenses which have to treat astigmatism is the presence of a cylindrical dimension of a lens, which is responsible for correcting the two main meridians of the eye. Of course, astigmatism can also be corrected by surgery, which is an option which you must discuss with your eye doctor and decide if it’s the right one for you.

Due to the large number of people affected by astigmatism, more knowledge on this topic is clearly needed among the general population. Frequent eye exams are thus necessary in order to detect the condition early and start its correction, regardless of the treatment you choose. Complications are very rare, meaning that you have no reason to panic if you suffer from astigmatism. Talk to one of our optometrists at Metro Eye Care to set up a consult as soon as possible.