Astigmatism is a condition related to the eye’s curvature. Ideally, the eye’s lens and cornea (front part of the surface of the eye) are smooth and consistent in shape over the entire surface. However, with astigmatism, there is irregularity that can result in a perpetual blurring of the vision.
Astigmatism is surprisingly common; some estimates indicate that up to 9 out of 10 people have at least a slight degree of astigmatism. Fortunately, there are solutions for this refractive condition ranging from toric contact lenses for astigmatism to surgery.
Be aware that astigmatism is technically not a disease of the eye; it’s a variation in eye shape that can occur in anyone, but it seems to run in families. One of the best ways to determine if you are at risk for astigmatism is by checking your own family tree to see if any of your relatives have this issue. If more than one person has, it might mean that you are predisposed to it. Lens and corneal disturbances can also cause astigmatism, which can range from moderate to severe.
There are a range of symptoms that characterize the condition of astigmatism including the following:
Blurry Vision. The most common astigmatism symptom is blurry vision occurring at any distance.
Visual Distortions. Astigmatism can also cause distortion in vision manifesting in horizontal, vertical or diagonal lines appearing bent or wavy.
Squinting. The need to squint in an attempt to focus one’s vision or to relieve eye fatigue is another common symptom of astigmatism.
Eye Irritation and Discomfort. Frequent occurrences of eye irritation and discomfort may also indicate that astigmatism is an issue.
Headaches. Persons with astigmatism often experience headaches that can be persistent and frequent.
Fatigue. Eye fatigue and general fatigue can be a symptom of astigmatism, especially if it occurs in combination with any of the other symptoms on this list. Chronic headaches and squinting can contribute to lowered energy levels and a general feeling of malaise.
Of course, these symptoms are not exclusive to astigmatism and could indicate a number of other health conditions. The number and severity of symptoms will also vary depending upon if the astigmatism is severe, moderate or mild. Only an ophthalmologist can determine the definitive source of problems related to the eyes and vision. If you experience any of these symptoms regularly, a comprehensive eye exam can help to determine the source.
Some people erroneously believe that astigmatism is caused by not using enough light while reading, sitting too close to the television or by habitual squinting. The truth is that astigmatism can be present at birth to some degree and is often hereditary. A mild case of astigmatism may stay the same and never worsen over time. In other cases, it will progress and get worse, requiring toric contact lenses or other corrective measures. Conditions like eye disease, an eye injury or surgery can also exacerbate astigmatism.
The lens and cornea of the eye are responsible for focusing what is viewed by refracting light from the images to the back of the eye (the retina.) While normally-formed eyes have a smooth, rounded, consistent front, an eye affected by astigmatism tends to be more oval shaped, leading to distortions. Light literally scatters a bit as it passes through the eye, causing a blurry image on the retina. This results in more difficulty in seeing at any distance.
Diagnosing and Treating Astigmatism
Astigmatism is diagnosed by an opthamologist via a keratoscope or keratometer and/or a visual acuity test to check corneal curvature. While mild astigmatism may not require any action, moderate to severe astigmatism can be addressed with eyeglasses or toric contact lenses for astigmatism. Refractive surgery is another possibility for treating astigmatism.