Original sentence: Essentially, blurry glass is used to add a small blur to the image.Low-quality lenses can also be considered a form of optical low pass filtering.This prevents high-frequency information from getting through and causing aliasing.To avoid aliasing, optical low pass filtering is necessary (although not necessarily implemented in all camera designs)
Edited sentence: A calculated amount of blur is intentionally added into the optical path by an antialiasing filter, essentially a blurry glass.In some designs, the antialiasing element is integrated into the lens optics, or in some cases, the antialiasing element is omitted for cost reasons.The blur removes or reduces high-frequency components of the image before they can reach the sensor, preventing them from introducing aliasing artifacts into the sensor's output.To avoid aliasing, optical low pass filtering is necessary