Netflix flashes/flickers, back light dimming issue in fullscreen

When you watch a video at Netflix in Fullscreen, sometimes screen flickers/flashes briefly and then it’s normal again. There is also weird background dimming issue when there are subtitles on. When the screen is dark or with dark backgrounds, screen flashes when subtitles come on the screen. Both problems have happened since Mavericks, last build that doesn’t have this problem is Yosemite. This happens in Safari and Chrome with Macbook Pro 13 early 2015. Dimming issue is in youtube too. When in fullscreen light targets get even lighter like for example face and you can hardly see the face when this happens.