I find that one some drop shot par 3s, especially if the tee box itself has a sheer drop, I am uncomfortable making a swing.
One that comes immediately to mind is the 9th at Quintero, where all the boxes are small and drop off immediately.
I'm not especially prone to losing my balance when I swing and in general I;m not bothered by heights. But I've definitely on multiple occasions hit poor shots due to a lack of conviction in the follow through when near the precipice of a steep drop off.
I have suffered bouts of vertigo, and like Matthew was unable to make a proper swing at Mountain View's drop shot par 3 (Boring, OR). I would wrap my follow through around my body, thereby closing the club face, and suffering the results. I should have gone back to the blue tee which was not on the cliff top edge.
I managed the drop shot ending the back 9 at Milton-Freewater, because the hole is so short all that is needed is a half swing with a sand wedge, and the tee was not set forward on the cliff edge. After hitting, I crept forward to see that I was on the dance floor before descending through the canyon to the lowlands. This hole would qualify for a topic "What is the most roundabout route from tee to ball?"