I recently baught a set of 3 Harper Collins Lovecraft omnibus books I used to own as a kid, and have been enjoying reading his works again; but I was wondering if anyone can help me identify another mythos book I read around the same time. It would be nice to read it again, if it is still available. Unfortunately, my memory is rather sketchy at best.

What I do remember is that it had a bright yellow cover with red titles and no illustration, although I could be wrong on that last point. I recall little of the plot, but the main character didn't have any eyes and always wore dark glasses. I think I remember a scene where he used dynamite to blow up a Dagon idol, or something similar. He also visited a library on another planet?
I know it's not much to go on, but I registered here in the hopes that maybe one of you mythos scholars can point me in the right direction. Any ideas are greatly appreciated.
Regards,
Munin