Can Dark Window Tint Help Lessen Sun Exposure and Help Manage Melasma?

I have the darkest window tint on the market on my car windows, partly because I have Melasma over my entire face and want to lessen sun exposure while driving. Of course I use 30spf sunblock everyday but I live in sunny California and spend lots of time in the car. Does the dark window tint help, or am I fooling myself? The police don't like dark window tint but I feel it's a "medical" necessity.