The rokid max glasses can be adjusted from 0.00d to –6.00d for nearsighted users. you can adjust the display definition for each eye with the knobs above the glasses. it is suggested that you close one eye and adjust the corresponding knob until the display is clear, and then close the other eye and repeat the adjustment process.if your degree of myopia exceeds this range, you can use the prescription mount to add on lenses and get a clear image.