A Trifocal IOL is a step up from a traditional multifocal IOL . It is another type of cataract lens. In todays times all of us are ususally doing some activity at one of three distances. Near, Far or Intermediate. Intermediate being computer working distance. Thus, individuals may be looking for clear vision at all three distances and some thus opt for this cataract lens.
One must remember that the situations where we dont prefer to use Multifocal IOL remain for the Trifocal lens too.