According to a survey for the technology firm Olympus:

The average length of time a student could concentrate for in lectures was 10 minutes, according to the survey carried last month.

And a third blamed lack of sleep and being overworked for this.

Many students had been forced to take up part-time work to make ends meet.

Among the students surveyed, 13% admitted to missing up to five hours of lectures a week, while 17% said they had to prioritise their part-time jobs over lectures to be able to support themselves. […]

Nearly half of students feared they would finish with high debts and no jobs, according to the study.

BBC: Students only have ’10-minute attention span’

(via Beerken’s blog)