I feel like I learned something about this subject last month. My entire life, I never had any problems with sun and have an olive-colored complexion. But recently I spent way too much unprotected time in the sun in Brazil and the skin on my forehead began to show some spots of pigmentation discoloration. My own fault. So, I was not too happy about this and went to see a dermatologist about it about 3 weeks ago and she really educated me. It counts as a "specialist" for health insurance purposes, so you got to spring $50 for the copay (United Healthcare).
To clear up the pigmentation discoloration, she prescribed something called Tri-Luma Cream. It's a bleaching agent composed of fluocinolone acetonide, hydroquinone, and tretinoin. Got to apply it every night for a month or so. Since this type of problem is not considered a "medical" problem, it's not covered by health insurance. And the little tube of cream costs $120. Damn.
Regarding sunscreens, she said there are two categories: chemical sunscreens, and mineral ones. The mineral ones have either zinc or titanium oxide as the important components. They work as "reflective" agents: they reflect the suns rays. The chemical sunscreens work by absorbing the suns rays (not reflecting them) and channeling them off as heat.
I was told that both chemical and mineral sunscreens are equally effective, and it's just a matter of preference which ones you want to use.
I prefer the chemical ones, since the ones with zinc or titanium oxide leave a white-looking patina on my skin.
From what I was told, as long as the SPF levels are 35 or higher, you are good to go. In the summer, level 50 would be better, and in the winter you can go down to 35 if needed.
So, from what I understand, it doesn't really matter which brand you use, as long as the SPF levels are appropriate. Some have fragrance, some don't.
Anyway, I have to go back to dermatologist in a couple weeks...this Tri-Luma cream seems to be working on getting the pigmentation problem under control, but we'll see.
What I learned from all this is how important skin care is. I never spent any time or attention to the sun's affect on my skin my entire life, and out of nowhere this problem developed. So, learn from my mistakes. Use sunscreen ALL THE TIME. It will keep you looking young and prevent any problems.