Thanks for the info. I'm not really worried about heat blocking. I just want to keep the sun out of baby's eyes (and mine too). And looks aren't really my concern either. I'm not going to write off 35%+ or mixed levels just because they don't look "cool". As long as they functionally do what I want then I'm OK with it. For blocking light I know that I probably want something dark, but I am not willing to lose an excessive amount of nighttime vision. And I know this part is subjective. Right now I think somewhere in the 20-30% range would be good.