If you are looking for a non-prescription eyeglasses, so there is no need to copy the prescription of your current lenses but they need to find the lenses with the same size of your old lenses so as to be fittable for your old frame. But it is hard to find the same size lenses and worker in optical stores will take the risk of breaking the lenses when taking out and putting in. The easist way for you is to find another non prescription pair with the frame you like and the new non-prescription lenses.
It is possible to take your current glasses to the original place where you bought the glasses and have new lenses made
with the same prescription as your current lenses. They will make your glasses based on your old pair.
Of course, yes. I just took my old glasses to my local store and asked them to process my new rx glasses according to the prescription of the old ones. But if you've got your prescription for a long time, more than 1 year or even longer, i suggest you take a new eye exam.