Appropriate glasses prescription for general machining? Near, far, in between?

I am 62. Electronics is my day job but I have been learning some machining and CNC and taking some classes in the fall. My vision is corrected to 20/20 in both eyes but lack coordination between eyes for depth perception - hasn't been a problem flying (private pilot) and other things. I have "mono vision" glasses - near correction in one eye and far in the other. Apparently this isn't common in glasses but is common in contacts (my eye guy tried to explain why the difference but I didn't understand it). Anyway, that works well for me. I am going to be getting some prescription safety glasses and wondering what I should get for a prescription. I can ask the ophthalmologist for whatever distance makes sense. Wondering if a far prescription doesn't really make sense for the machine work so maybe a near and something like 6 ft correction? I would still need far for classroom work unless I sit in the front row. The difference between eyes and prescription isn't huge - I'm not blind at the other distance - just not completely clear. Any advice? Changing glasses occasionally is ok but would like to minimize that. My near correction is good from about 6" out to about 30" very clear and gradually worse beyond that so perhaps my existing near and far corrections are ok.

I also have the mixed diopter thing going on. Add in bifocals and it gets sort of weird. A pair of "computer" glasses works well for me in most shop situations, far distances are not perfectly sharp, but on occasion I've accidentally driven with them and not realized it at first. Before retiring I had a clock and watch restoration business. A pair of single vision glasses optimized for 13 inch distance was very helpful when doing small work on a watchmakers bench. As my near vision with these was highly corrected, I could put on optivisors including the highest power version plus the add on magnifier and not induce bad eye strain. Very helpful for doing very small machine work for watch and small carriage clock scale stuff.

Thanks Stan. I tried bifocals and do lots of computer work - they just didn't work well so I went to monovision (at least that's what I have heard it called). I am going to get a vision checkup in a few days and my immediate goal is to figure out what distance prescriptions to ask for. I can get several and don't need to get glasses for all but with the prescriptions I then have the choice of which ones to get.

I have similarly defective eyesight and have used varifocals for some years.I think the approach would be to get the sight correction that works best and to make sure the lenses are able to cope with the working environment.You need to make a good estimate of the range at which you will be working and it is easier with a small machine as the range can only vary within a small range of limits.The type of work may make a difference as the plastic lenses can attract dust if machining wood or some plastics and metal swarf follows a different trajectory being denser.It could be that a clear visor over normal glasses would work well.