Common Vision Conditions Affecting Children |
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| Astigmatism is not a disease, but rather, a vision condition that is quite common. Astigmatism is a vision condition usually caused by an abnormal corneal curvature. With astigmatism, the cornea, front surface of the eye, is more oval shaped rather than spherical. This causes light rays to focus differently in various meridians of the eye and not brought to a single focus. This may cause objects at all distances to appear blurred or distorted. Astigmatism often occurs in conjunction with other refractive errors such as myopia (nearsightedness) or hyperopia (farsightedness). The causes of this irregular shape are unclear. In some cases, it may be hereditary or it may result from such factors as pressure of the eyelids on the cornea or excessive use of the eyes for near work. People with severe astigmatism will usually have blurred or distorted vision. Those with mild astigmatism may experience headaches, eye strain, fatigue or blurred vision.
Astigmatism can be effectively diagnosed in a comprehensive vision examination and optically corrected with lenses (spectacle or contact lenses). Soft contact lens are not able to correct astigmatism unless they are a special type known as a toric contact lens. Large amounts of astigmatism often can only be treated by rigid contact lenses. Astigmatism may change slowly, however, regular optometric care will ensure that proper vision is maintained. Some common signs and symptoms of astigmatism include:
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