If you are chucking heavy weight Clouser Minnows, that fly can SMACK you at any time during the cast. And a hit to the head is bad enough, think of getting that size 6 or 4 hook in an eye - especially if you didn't pinch the barb well enough. I don't even know if an eye that gets hook can be saved for that matter.
Of course if you get polarized sunglasses, you get the added bonus of glare reduction and site fishing.
So go buy a pair of sunglasses that you can afford and get polarized too for that added benefit. They range from as cheap as $5 and go up over hundreds of dollars if you'd like.
You only have two eyes, the glasses are not totally for fashion, they serve one good purpose, to keep the eyes you have.