F.B.
I think shades is a good idea, it allows their eye to rest as well. But I wouldn't give up yet, my son went through this at least 4 times so far (he'll by 4 in May). He would go a week or so without napping at all, at school he would just lay on the mat awake. Then for no real reason, he would start napping again. I think they all go through these phases. Good luck!