Just discovered a small scratch on my iMac 27" 2011 model LCD panel. Must have happened during cleaning. Kicking myself. Its on the panel itself not the front glass Its small but just north east of centre on the panel and exhibits a rainbow effect which changes when you move your head so its sadly very noticeable when in finder or office apps or movies. Any ideas on how I get rid of it or at least minimize the effect. Cheers.