Affecting Real-Life Sanity

[Kurton]

This can also probably be done with much subtler visual changes, maybe none at all. For example, I was once out in a dense field, working to pull up invasive brush in in the midst of tall grass and weeds, and the weather was pretty damn cloudy, so a lot of grey. Then the sun decided to push through the overcast, and brightened everything, and then I just noticed, all of a sudden; there were yellow dandelions everywhere. And I had not even noticed them just minutes before, as though they had all sprung up in no time.

This effect may be hardest to pull off in horror, however, as it entails not immediately seeing something while indeed looking almost straight at it. But it is certainly in league with that "It wasn't quite like that before o.O"

Whatever, just throwing ideas out.