horse portrait

hi,
For practice ,I tried to draw the eye of that horse today  , based on this original picture of HorseStockPhotos
www.deviantart.com/art/Buckski…

 I think that I realized quite well the gaze but I didn't want to make all the face in the beginning with just a paper size A4 (that's too small) .So this portrait is not finished ...






To  In this artwork I wanted to achieve realistic look of the face .
I just want someone to critique my shading (mainly the face ) and the way that I did the hair because I had the hardest time trying to blend that part smoothly !I would like to know if I have improved in my skills , and what my errors actually ?