I've been having a very hard time finding a good sunscreen for my very sensitive skin. I know there a lots of us who have the same problem. It's probably easier to find a cosmetically acceptable protective sunscreen if you can find a "chemical" (organic chemical) UVA protector that your skin can tolerate, like mexoryl or Neutrogena's "helioplex" (stabilized avobenzone). Those of us "Sensitives" who turn to physical blocks like TiO2 and ZO have a harder time finding cosmetically acceptable protective products.

I do not have "The Answer" but I'd like to share some links for those on the same quest.

There is a lot of information online about various sunscreens, and about the need for both UVA and UVB protection -- that is, protection from the broad spectrum of sun rays, to prevent damage, ageing and cancer. As most of us know, the US sunscreen SPF labels only tell us about protection from UVB rays, which can burn/tan the skin, but not about protection from UVA which can cause skin cancer.

Here are some helpful links:

makeupalley.com/user/notepad/sunscreenFAQ/
www.makeupalley.com/user/notepad/sunscreens


If one knows the active ingredients of the sunscreen, one can calculate the UVA protection using the calculator on this site:
www.cibasc.com/pccibasunscreensimulator (registration required to use)

So, for example, Clinique's Almost Makeup SPF 15, which I like well enough cosmetically, has only 7.6% TiO2 and would fail the Australian sun protection standards, according to this calculator. So, I would need to use a better sunblock underneath the Almost Makeup to be adequately protected.
I do not completely understand the various standards around the world, or the details of this calculator, so I doubt I can answer any questions you might have. There are more links on the makeupalley pages and on the CIBA site that have lots of information and scientific background.