Conclusion re "office intermediate" computer/reading multifocal spectacles: using a Mac with a 20-inch monitor, I can now focus clearly when the screen is a metre away from my eyes and still get in close enough to read my Kindle Paperwhite close-up. I also chose an anti-glare, anti-smudging & scratch-resistant coating on the lenses.
Previously with the reading glasses only, the screen couldn't be further than ¾ of a metre away and even then was getting a tad fuzzy.