I think I should invest in some scientist-eyeprotectors rather than rely on glasses, though
You definitely should. They're not terribly expensive (usually somewhere around 5-10$). Also, get the kind that's designed for use in a chem lab, not the ones for like woodshop and stuff, because some of them have holes along the sides (they had posters in all the chem labs where I went to college, where they put the goggles on a mannequin and splattered them with red paint. Not pretty.) Also, safety goggles are better than safety glasses.
Also, while vinegar is great to neutralize lye spilled on countertops, floors, etc, the best first aid measure is to run a LOT of water on the affected area- while it *is* basic, and acids will neutralize bases, vinegar is a weak acid and fairly dilute (usually about 5% acid), while the lye solutions used in soaping are fairly concentrated. By putting the area under running water, you dilute the base and wash it off the skin. A lower concentration of base (ie, diluted) has a less basic pH, and when a minuscule amount of base is dissolved in a lot of water, the pH of the water will be neutral.
The first aid measures given in the MSDS sheet (Material Safety Data Sheet- basically tells you how to safely handle and store a chemical) for NaOH (lye) state to flush the area with water for 15 minutes. That's probably longer than needed for a small drop or two, but make sure you've fully rinsed off the area, and remember that it's ok to be a bit too cautious. This just gives a frame of reference for how long to run water over it before you can be *sure* it's good.