What's the Difference Between a Sun Screen and a Blockor?

Modern sun screens are chemical sun screen only started to get sold in the 19 twenties and thirtiesderstay read that, m they were first marketed a s p f two. But alsoswer hat would make us gray scale. We am i going crazy? No, yes. Jus herei can explain it, somon, by wearing something that blocks the visible light, they locks the visible light from hitting your skin. Yeas. And that's why, like, now, most now wa er polite is what we're saying is like the extra ya, ye.