One of the random quirks about me is that I generally can't survive outside without sunglasses. My eyes are extra sensitive light.
I'm also the kind of person who loses and breaks things frequently. So my standard for sunglasses is to buy many pairs of cheap glasses until they all break or dissapear and then I buy more.
I don't think that will work for my hike. For one thing, I will likely need something that is close to my face to protect my eyes from dust and bugs as well as UV rays.
I also can't afford the pack weight of carrying a bunch of extra pairs. So I may have to actually invest in something more sturdy. At least I will be wearing them every day, so there will be less chance of losing them.