At first, Eye strain is the most important factor that canuse the visual defects especially refractive errors. So to prevent astigmatism, you'd better avoid eye strain and stress. Next,eye rubbing the eyes too much will increases the risk of hurting the eyeâ€™s cornea and astigmatism is caused by irregular corneal surface, so you must avoid eye rubing. Furthermore, you should read in an appropriate light because too little or too much light will cause eye strain so that they should be avoided.
Eat healthy foods which contain much vision-beneficial substances, e.g. vitamin A, vitamin D, lutein and zeaxanthin etc. Fruits and vegetables are widely recommended. Moreover, many eye care practitioners suggest that doing eye exercises every day is helpful in preventing visual refractive errors. Some others even believe their effectiveness on vision improvement.