Foxhunter if your deteriorating vision is due to normal age related changes then you have three choices,
1. increasing the lighting to improve contrast, remember the inverse square law which basically means that even a relatively weak light very close to something is going to be much more effective than a bright light far away. Fluorescent or LED are both better as task lighting than incandescent lighting and do not generate as much heat. Think about glare sources, reflections and directional lighting. You might also be able to improve contrast by darkening the scale measurements for example and lightening the background, black marker rather than pencil etc.
2. Magnification, as well as the head mounted loupe, you can also get hand and stand magnifiers with and without illumination, that is angular magnification, you can also have real magnification by making the item you are looking at bigger e.g. a larger scale with bigger numbers ( if that is possible).
3. More powerful reading glasses, however as you increase your reading addition you will reduce your working distance, so if you go from a +3 reading add to a +4 you will reduce from a working distance of 33cm to 25 cm although you will gain a bit of magnification due to distance magnification as you move closer to the object whilst staying in focus.
Sorry if this is rude but if you are of the age where you might be developing cataracts and have early cataracts you might want to think about having them done. As your lens ages it will discolour, reducing contrast and increasing glare well before a noticeable loss of vision.
My apologies if I am teaching you to suck eggs.
