The problem as I see it is that the diopter system only has a limited number of different profiles. So if you fall in between a diopter (need more than a 2.5 but less than a 2.75, say) the lenses won't be perfect and you'll have eyestrain.

Presbyopia hit me about 10 years ago. Some people I know use all-day contacts for distance vision then wear glasses on top for computer use and reading. I'm considering it.