What are the annual sales of designer brand sunglasses in department
stores by brand? The brands I am interested in are: Kate Spade, Calvin
Klein, Donna Karan, Ralph Lauren, Nicole Miller. One or two would be
enough.

I am not able to answer your question, but may have some useful
information.  I worked for Ray-Ban from 1986 - 1994 introducing new
high end sunglasses.  A couple things you may want to consider:  The
department store market for sunglasss is small, but for the designers
you mention it would be a bit larger than usual.  The real sales these
days come from sunglass hut (now owned by Luxottica which owns Ray-Ban
currently and many of the designers names you mentioned).  Donna Karen
was co-branded by Ray-Ban in the early 90's but did not sell very well
(below $1 million annually world wide for a typical DK item).  A
strong seller would sell approx. $5 million per year annualy world
wide in the first year after introduction.  A typical new product
would sell between $1 - $5 million.  The numbers I am giving are not
for just department store sales; no idea on what just department
stores sell.