When I installed very high quality (CRI 98, R9 94, virtually flicker free) light bulbs to one of my apartment rooms I had headaches and felt occasional confusion for about a week while being in that room, so I had to slowly increase the amount of time the light bulbs were turned on for. To my understanding my brain was very used to the way objects and lighting looked in that particular room so it needed to rewire some knowledge given that I've spent many thousands of hours in that room with previous light bulbs.

I'm curious if a younger me would have adapted much faster.