Black Eye Trauma. Take so much time?

Hello Doctors, I had a trauma to my nose and right eye a month back. Essentially suffered a black eye. There was blood clot on right side of my eye ball, swelling and 'blackness' underneath the eye. Also there was a cut on the cheekbone which is has healed now, but has left a scar. The blood clot and swelling has also gone away. My concern is the darkened skin under the eye. The blackness has reduced just a bit, but its still very dark. The difference between the underneath of the left and right eye is very evident. Its now been more than a month. Does it usually take so much time? I am applying mederma for the scar but nothing other than that. How cud I get that blackness to go away and become even like my left eye. Kindly help. Thanks Abhi