I think you need prescription eyeglasses to correct your vision so that it will not disturb you when learning English. Although the prescription eyeglasses are not very cheap, but you have no other choice if you do need the eyeglasses. However, there is an online store selling very cheap eyeglasses. It is Zenni Optical. Zenni: the #1 online eyeglasses store is the right place for you because they sell eyeglasses from as low as $8. Although many eyecare professionals will not give you PD information, and since PD information is very important to purchase prescription eyeglasses from any other supplier including Zenni, you should try to get it even if you have to pay for that. From the discussion I found at Optiboard.com (Got Asked for a PD Today (First Time)), I conclude that there is NO PD for you from Opticians. Or if you intend to do it yourself, here I would like to give you brief description about PD.
What is PD? PD is a short for Pupillary Distance. It is the distance between the pupils of your eyes, i.e. the center of your left pupil and the center of your right pupil. Then you can measure your PD manually at home.