Is it me or does Prime has some slide down shades?

Yeah, I've noticed that.

In G1, some transformers had full one-piece visors that could slide down over their individual eyes (not sure about the later continuities but wouldn't doubt it was there as well). My interpretation of this was that nearly all transformers had it and some just constantly had them on all the time (i.e. Jazz, Grimlock, et al.). This seemed to be somewhat echoed in the headsculpts of the BT/Alt line. Perhaps this is a similar idea except that the movie has these actual robotic eyes as seen in Prime's face design above with individual eyepieces that slide down over them and look something vaguely reminiscent of the normal eye design traditionally seen up until the movie.

yeah arcee had that visor in the movie

Movie Prime reminds me of the Prime from that old box art that was on the back of early G1 toys. That one had eyes that were different from the toy and the cartoon Prime.

Basically, what you are looking at are his eye lids. If you look at the design you have the actual eye, with iris and pupil partially coverd by moving metal plates which protect it from damage and assist in diplaying emotion. I believe there is also a transparent plate framed within those plates as well.