Camera flashes are very painful for me too.
They have ruined many a social occasion for me.
It's yet another thing I find that non-KCers don't get and I often end up feeling like they don't believe me.
Driving down a dappled lane is a nightmare. I don't drive, but if I find myself in that situation I sit there with my eyes closed. I also know which side of the bus to sit so I'm out of the sun depending on the time of day. To make me sound extra sad I also know exactly where the sun will catch the side of the bus I'm sitting on and close my eyes in anticipation.
What I find the problem is going from one level of light to another. If you stick me out in the sun I will adjust. If you stick me in a darkened room I'm fine. When I'm not fine is when I'm moving from one to the other. It takes me ages to adjust. Sometimes I don't at all and end up with a killer headache. I have no idea why this should be. I have asked my doctors about it many a time and never got a clear answer, but I guess as this is how things have been for me for more years than I care to remember it's pretty much permanent.
I minimise the impact by planning ahead (as much as is feasible), never being without a hat (sometimes indoors as well as out) and my prescription sunglasses. Oh, and a good dose of 'the glass being half full' attitude to it all.