Display screens for marine electronics shouldn't be cleaned with just anything. Harsh chemicals, like window cleaner, can cause the screen to get hazy or lose its anti-glare properties. Rags with, " hard," thread or hems can scratch screens; heck, even paper towels will scratch a screen.
Usually, I use water and a soft cloth. But the screen in the following video defied my efforts. Click play to see the result of using Star brite Screen Cleaner and Protectant.