The rage eye is when you have beaten that gang 3 times in a row and rage lasts for 7 days 

We've added a new feature to the gang game play and it's called Rage. 

  

If one gang kicks your ass 3 times in a row - Your gang will automatically go into "Rage" mode in the next fights against that gang for one whole week. 

Rage mode gives you additional bonus to Cock Fights and Battles - but only against the gang that caused your "rage".

http://hotcandyland.com/hotline/3652/rage-new-feature?show=3652#q3652