Answer: Over time, wiper blades wear and crack and need to be replaced. Dirt can also build up on the blades. Either way, over time, wiper blades don’t slide back and forth over the windshield as evenly. They will leave streaks and clean poorly. It is necessary to have good wiper blades to keep a driver’s windshield as clear as possible. It is especially important to have good wiper blades during the winter to ensure a clean windshield from all the wet and salty roads. Worn wiper blades can also lose chunks of rubber from the blade. If a blade loses a large chunk, then one of the blades arms can damage they windshield by scratching or nicking it.