It looks to me as if the problem is UV clouding of the plastic lens. If this is the problem then it can easily repaired by removing the lens (the surround will unclip) and polishing both sides of it with Autosol metal polish. It will make a beautiful job of it. The other two potential problems are loss of LCD contrast; this is set by the LCD excitation voltage (not user adjustable) and the loss of backlight illumination. I have not taken this display apart but the display illumination is usually a (couple) of LEDs integrated into the display panel. Both would therefore be resolved by replacement of the LCD module.
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