We have had to have them (seeing glasses and prescription sunglasses) repaired at least 10 times in the last two years with no cost to us. I kind of think the optician might regret having sold us that particular policy. :P (Seriously though, the staff there have always been gracious and understanding whenever we take the glasses in.)
So, yeah, if you are considering insuring your kid's glasses, go for it. :P
That is Farmer Boy, aka Junebug, in the icon, also. My how they grow.