It is necessary for you to have a thorough examination by an ophthalmologist first of all. Night blindness can be caused by myopia, cataracts. If it is caused by myopia, you can fix a prescription to help you see more clearly in poor light. In the case of cataracts, you then need to receive a surgical treatment, after which you will see clearly in dim light. If it is just due to lack of vitamin A, the night blindness can be treated with vitamins, nutritional therapy and medications. You can eat more foods which are rich of vitamin A such as egg, animal liver, carrots, tomatoes, spinaches and so on. Do not strain yourself and eat pungent and hot food. You should also give up drinking and smoking if you did.