The goal of natural vision improvement is to use your natural vision. So, in general, we encourage you to leave your glasses or contacts off when you are in a safe environment doing something simple; in other words, when you don’t really need them. We prefer glasses to contacts because they are easier to put on and take off and do not cover the eye. We both used to wear glasses and understand the frustration and fear when you first take them off and the world is blurrier, but as time goes on and as you do the exercises, things will start to sharpen up.
You can also slowly wean yourself off glasses making it easier to adjust. Find an optometrist who will prescribe glasses that correct your eyes to 20/40 rather than 20/20. You will find that over time your eyes improve enough with these reduced prescription glasses to reduce the prescription even more.