I have a male dragon who favors shutting one eye, and has so since I got him in December. It is just his thing to do but I did take him to the vet for a wellness exam to make sure he was okay.
My female dragon slacked off on eating and started digging in corners so I also took her to the vet for xray or sonogram to see if she had eggs, rather than worrying her and wondering. She didn't.
Sometimes it turns out to be just one of those things.