The main cause of astigmatism is the change of corneal curvature.A normal cornea is not only smooth and transparent, but also has a complete hemispherical shape. When the curvature of the hemispherical cornea changes, like a worn rough lens, its surface appears uneven, irregular shape, and the external light can not focus on the retina
Astigmatism is mainly due to uneven cornea caused by the refractive abnormalities. This kind of situation needs to be controlled by wearing glasses. The following conditions such as long-term fatigue, often staring at the mobile phone, as well as the computer can cause astigmatism, so we should pay attention to regular work and rest to avoid staying up late.