Bifocals are special types of lenses which contain two prescriptions: one for distance and one for reading. It is much less common for children to wear bifocals; the usual reason is to help to relax an overactive close focusing system.Bifocals can he useful in treating some forms of shortsightedness. Some children who have trouble relaxing their close focusing (accommodation) may become shortsighted, however research in this area is not conclusive. Bifocals are also used occasionally with children and young adults in the case of convergence excess a tendency to over-converge or go cross-eyed. The reading segment of the bifocal lens allows the child to relax the focusing and convergence mechanisms when looking at close objects.