Never lose or forget your sunglasses again with SunCaps because they are built right into the visor. Each hat has a pair of stylish polycarbonate sunglasses that slide up and down through a slit in the bill of the hat to give you 100% UV A and B protection. Comes in a few styles and colors too:
I can’t say for certain but it looks like you can probably put your own pair of sunglasses in there instead of the included pair. Available for $24.99 from SkyMall.