Plzz help! how to change this back?

I dont know what i did but now i cant watch anything well on my computer..i watch things on winamp and now i open something its really white and foggy and its stressful to even watch.. If it was related to the whole computer then shouldnt my desktop turn foggy too??? but it didnt so im thinking thats not it?how to make the display normal... God bless you if you answer his sincerely.....