How Lightsabers Work

Howstuffworks – How Lightsabers Work:

A lightsaber user with a strong affinity for the Force has a distinct advantage in the latter situation. By using the Force, the wielder can anticipate the path of the blaster bolt and align the blade with that path prior to the bolt’s arrival. Using normal visual tracking to accomplish the same effect can be far more difficult.

via Herrn Cynx