I am happy to answer your question. For your condition, it's not rare for one eye is better than the other eye. Because one eye always work harder than the other eye. However, you may damage your eyes through some bad habits, for example, surfing Internet for long time can also make one eye is worse than the other eye. You could go to see the doctor to take a exam for your eyes, in that case, you will know the reasons for your condition. And you could make more exercises to make your eyes are good condition: try taking your thumb and placing it over an object far away with both eyes open. Then close one eye at a time and see which one is still covering it. You could consult your ophthalmologist make out some actions for your eyes. Good luck.