Other than bifocals, how can you correct your vision when you're both nearsighted and far-sighted?

By "farsighted" you probably mean "presbyopic." Nearsightedness (myopia) is where your vision is blurred at distance but typically good at near when not wearing glasses.

As the natural lens hardens in middle age, it can no longer change shape so as to focus up close. If your distance vision is sharp (i.e. not nearsighted), the presbyopia will require you wear some sort of reading glasses. But if your distance vision is blurred from being myopic, the near focus without glasses can be pretty good. This is because "near" is the default focal distance in a nearsighted eye. In other words, you can still be presbyopic but have good near vision -but only at the expense of the distance vision. If you then put on glasses or contact lenses (or have LASIK), the distance vision clears up but you lose the near vision because you are now at the mercy of the presbyopia!

One way around this is monovision: where one eye is corrected for best distance vision but the other is left a little nearsighted so as to preserve at least some of the near vision that comes with being myopic. Monovision can be achieved with contact lenses, LASIK, or with intraocular lenses (IOLs) if there is also the presence of cataract.

Another approach is PreLex®. This is where the natural lens, no matter how little cataract there might be in it, is removed and replaced with a special IOL that can focus at both near and far in the same eye. The latter is generally employed, though, in older patients who have at least some sign of cataract.