Strange brightness/contrast issue

[hopsiuping]

I am a proud user of lumia 820 for three days. Unfortunately, since yesterday my phone screen has become very bright and looks like it does not react on room light changes, even in the manual mode, darkest option is too bright. It is very similar to a purple screen problem with the Lumia 900. I attached a screen shot and photo for comparision. Even though a photo is not the best quality the issue is perfectly visible on it.

Removing the battery and phone reset did not help.
Is phone replacement the only cure for my phone?

Thank you,
Hopsiuping