The wearers may find difficult to get used to the lined bifocal glasses because the image jump from the far vision to the reading segment so quickly that you have no time to get used to them. And there is no intermediate vision in total presbyopia.
There are some separated vision areas in lined bifocal glasses. Therefore, some wearers can not get used to radical vision change with those glasses. Or some of them will suffer from very serious dizziness or headaches.