Astigmatism

Rugby Ball Shaped Eyes A.K.A. Astigmatism is responsible for blurred vision due to a difference in the focal power of the eye in different meridians. This results in some parts of the image on the retina being clearer than others. Blurred vision occurs at all distances, the higher the degree of astigmatism, the worse the blur. It is most noticeable when trying to see fine detail.

What causes Astigmatism?

The eyeball is not completely spherical like a football in astigmatic patients but more like a rugby ball with a steep and a flatter meridian. The greater the difference between the curvatures of the eye, the greater the degree of astigmatism. It can be associated with long or short sight or can occur alone.

What are the symptoms of Astigmatism?

The symptoms of astigmatism vary depending on the severity and the type of task attempted. In mild astigmatism, it may be difficult to concentrate on near print and close tasks, eyestrain and fatigue and also headaches at the end of the day may occur. In medium to high levels of astigmatism, achy and burning eyes may interfere with concentrated tasks and irritability may follow sustained concentration. What can be done to manage Astigmatism? Corrective spectacles (or contact lenses) are needed to focus the retinal image properly and enable clear vision. How much spectacles need to be worn depends not only on the prescription but the individual's work and lifestyle. A person with mild to moderate astigmatism may only need spectacles for concentrated tasks such as computer work, reading and driving. A high degree of astigmatism needs spectacles to be worn more or less all the time. In children with high levels of uncorrected astigmatism the blurred retinal image may interfere with the visual system development leading to the child never attaining full adult visual potential.

Constant wear of the corrective spectacles is essential from as early an age as possible to try to prevent permanently stunted visual development.

Can anything be done to stop Astigmatism getting worse?

Astigmatism is due to a difference in the curvature of the eyeball and tends to remain fairly static throughout life. An exception to this is a disease of the cornea called Keratoconus that causes increasing astigmatism, but this is not a common disease.

Can patients with astigmatism be fitted with contact lenses?

Yes, in fact many patients have low levels of astigmatism which allow normal contact lenses to be fitted. For highly astigmatic patients, special lenses called torics are needed to get good vision and fit.