Fly a low wing aircraft!
One trip a while back, me and a friend were flying over a desert in a 172, at 12,000'. It was turbulent and the atmosphere was very murky, you couldn't see that well ahead, but you could see down ok. When we landed he confessed that he started getting a bit of vertigo....which was funny, as I had too.
Never experienced this in a low wing a/c....probably as the wing stops the 12000' view directly down
Not experienced it on a gin clear day at 12000 in the desert either, in a high wing or low wing......