They have a film over them to prevent glare - but using water or windex does not work. It leaves streaks in the monitor which are extremely noticeable, and annoying.
I have read somewhere that you should avoid spraying windex directly on any monitor, since it can leak into the insides. And I have heard that you should use alcohol swabs for such monitors with this film that streaks like crazy. Maybe because it evaporates so quickly - I don't know.
What do you guys think (actually, what do you guys know?

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