From your post I gather you may need 'bifocals' with the 'reading' part being plain glass. If you can see the instrument panel in focus (i.e. w/o any correction), then you should probably tell the optician to create glasses for you with a slightly higher-than-normal border between the 'reading' and 'distance' vision parts (normal bifocals have a rather low 'reading' inset which will probably come in at about two-thirds up on the panel - not a good thing to have).