If a pane of plexiglass in your home has become foggy over time, you can try making it clear again before you go through the expense of having it replaced. Plexiglass is a high-grade acrylic often used in place of glass because it is much more durable. However, as any plastic ages, it will show wear and tear with very fine scratches that make it appear foggy or cloudy. Using the right procedure, you can restore most of the clarity of your plexiglass.
Wipe the surface of the plexiglass on both sides with a clean, dry, lint-free cloth to remove dust particles. Since the plexiglass is cloudy and porous, you need to remove any loose debris so it doesn't lodge into the tiny cracks and make the cloudiness worse.
Polish the foggy-looking areas of the plexiglass in gentle circular motions with a polish made for plastic and a clean cloth. Plastic polishes come in different variances of strength, like sandpaper comes in different grits. When removing cloudiness or extremely fine scratches from plexiglass, you should start with "No. 2" and then use "No. 1" to make the plexiglass shine again.
Clean the plexiglass with water mixed with a mild, ammonia-free detergent and a soft sponge or cloth. Strong chemicals such as ammonia will contribute to the cloudiness of a piece of plexiglass.
Remove the water from the plexiglass with a clean, dry, lint-free cloth.