Clark and Al- thank you both so much for your replies!

So first, Al: actually, I was not able to see the object (I guess I
should have explicitly stated that in my original post, sorry for the
confusion.) But I do definitely agree with you about dryer fires,
which was why I was as concerned about this as I was.

And Clark: I poked around that site, and lo and behold...

http://www.applianceaid.com/fanblower.html

So I guess I'm not the first person that this has happened to!
Well, I had the husband remove that back panel of the dryer according
to the instructions on that page, and- voila! Not only was he able to
retrieve that object that was from the sunglasses, but he also got out
from there a small pencil, a paper clip, a toothpick, a bobby pin, and
a whole, whole lot of dirt and lint!!

So thanks so much guys, I am so very grateful that this problem is now
taken care of (it's a load off my mind, and I now know how to deal with
this sort of thing in the future, and I now have a great online
resource to consult in the event of any other appliance-related problem
that may come up in the future!) Thanks again.