Well, it depends. This mainly depends on what kind of eye injury you have got. As far as what I know, astigmatism is usually caused especially when you wear your contacts. Because the lenses can usually hurt your eyes. Besides, there are also a lot of other people who get this disease because they just get it since born. In a word, astigmatism can be caused by an eye injury, surgery or certain kind of eye disease.
Astigmatism is an vision problem. People who suffered from it usually suffered from blurred vision. And this is caused by the not curved properly about their cornea. And this can be happen for both children and adult. And injury can cause astigmatism. Besides, some vision problems such as myopia, hypermetropia and presbyopia can also be the reason of astigmatism. Luckily, eyeglasses can correct it.