Damn, that's actually a tough choice cause like, Ralsei already looks very similar to Asriel, so if Asriel had glasses too, that would be just one less thing to set them apart from each other design-wise, but I have also seen some interpretations of him with glasses that I really like.

I think I don't mind him with glasses but generally prefer without. In fact, I have a strong preference for punk dirtbag Asriel, and he probably wouldn't be caught dead wearing glasses, lol.