Try tall frames that help create a shorter face, or broad frames with an accented top rim. At the same time, avoid all frames that may accentuate face length.
Check out http://www.firmoo.com/help-p-50.shtml for more knowledge about how to choose suitable frames for yourself.
You can have a look on this website http://www.fashionbeans.com/2013/mens-face-shapes-sunglasses-guide/ I think you may have the oblong face. There are some suggested sunglasses listed below the oblong face. If you think it is not your face shape, you can choose other face shapes that are similar with yours. The sunglasses listed below can go well with the face shape, you can have a try in any eyeglasses stores. Good luck!
You can have a look at http://www.forbes.com/2008/06/11/style-sunglasses-tips-forbeslife-cx_mt_0611style.html This article is very interesting because it listed many kinds of face shapes and have them wear a pair of sunglasses as well. Maybe the fourth pair of sunglasses is fit for you. Hope this helped!
I have found this on the internet for you. http://www.sunglasses-shop.co.uk/face-shapes.aspx there are some kinds of face shapes. After clicking the face, you can have a good understanding of this kind of face shape. And there are some glasses listed below to give you suggestions. If you think they are useful, you can have a try.