To prevent astigmatism in an early age, you should avoid eye strain. That is to say, you should not strain your eyes because too much eye strain will lead to refractive errors easily due to excessive eye use. Therefore using eyes in a proper way can help prevent astigmatism. Another thing you should notice is that it is better to read in in an appropriate lighting environment. Don't read in dim light, which can cause eye strain easily and lead to refractive errors. Rubbing eyes can also cause astigmatism. So you should avoid eye rubbing in order to prevent astigmatism.
As one of vision problem, astigmatism can be hereditary from parents and acquired. So, even if you have no astigmatism right now, you shall take good care of your eyes so as to minimize the potential astigmatism. Here are some tips. You shall take regularly break after hard working, studying, or playing computer games. Please not make your eyes fatigue. Again, please not read books in dim light environment. What's more eat food contains of Vitamin A, Vitamin, Vitamin C and Vitamin E to keep eye health.