It's... Sunglasses Day

Smoke tinted glasses were invented before 1430 in China.
But, they weren't for sun protection. Judges wore them in court so nobody could see their eyes and guess their opinion before a verdict was declared. Sunglasses as we know them today are a 20th century phenomenon.
In the 1930s, the military commissioned glasses that would protect pilots from sun glare.
But, they didn't become a real fad
until the 1960s when an
ad campaign said
"Who's Behind those Foster Grants?".