Astigmatism is a common vision condition that causes blurred vision. It occurs when the cornea (the clear front cover of the eye) is irregularly shaped or sometimes because of the curvature of the lens inside the eye. Most people have some degree of astigmatism. Blurred or distorted vision at all distances, headaches, eye strain especially when the eye has to focus for long periods, as in reading from paper or a computer monitor, difficulty in driving at night etc. are symptoms of astigmatism.