Masks or Shields?

[Kurt]

Here's an article that suggests shields "may be better" than masks.
https://www.aarp.org/health/healthy-livi...masks.html

I don't understand why there hasn't been any testing of this? I think there's a good chance shields are better but where's a little evidence? Shields also help with a number of issues like seeing someone's entire face or being able to drink (with a straw), potential breathing issues and a few others.

At the very least it would be nice to know if they are a valid option scientifically and legally (in some areas). In my town masks are required. As I said in my OP, I'd rather wear a shield. Can I legally?