Whenven you find youself cannot see far as clear as before, you should have your eyes examined to see if you are suffering myopia. If so, let them to do a careful examination, then them will give you their suggestions (whether or not you need a pair of eyeglasses to correct your vision) and your prescription paper which indicate the power of your eyes.
When you suffer myopia, you will find you can't see distant objects clearly.However, you can't determine how bad your vision will be.The only way that you should do is go to your eye doctor to have an eye exam.Then you will get your prscription and know how bad your vision is.