Using comps that don't have interior pictures?

[Victor Maddox]

This may seem like an obvious question/answer but I figured I'd ask anyway just to be sure. So for a multitude of properties in my area there are houses I find on Zillow/Redfin that look like they could be used as a good comparison via the numbers, but there are no pictures of the inside available to see what the home looks like. Should I just automatically write these off or is there some alternate way I don't know about to find out what the insides of these homes look like?

And another question, how far back is it usually acceptable to go when looking for comps? It's usually no farther back than a year right?