He's been in their lives for over 10 years. But it goes on, and it will evolve.â. Indeed, Grey's has persevered after the departures of several regular cast members, including Isaiah Washington, Sandra Oh, Katherine Heigl, T.R. Knight, Kate Walsh, Eric Dane, Chyler Leigh, and Kim Raver.
1 Some state that the average human attention span is approximately 5 minutes; others state that most healthy teenagers and adults are unable to sustain attention on one thing for more than about 20 minutes at a time, although they can choose repeatedly to re-focus on the same thing.
But in general, the length of our attention spans is decreasing. While we could pay attention to something for an average of 12 minutes back in 1998, by 2008 that number was down to a dismal 5 minutes.