Original sentence: Barium oxide only raises the refractive index.It is used in the production of certain kinds of glass such as optical crown glass.It replaced lead(II) oxide.Lead oxide was used to raise the refractive index, but it also raised the dispersive power
Edited sentence: It is used in the production of certain kinds of glass such as optical crown glass, where it replaced lead(II) oxide.While lead oxide raised the refractive index, it also raised the dispersive power, which barium oxide does not alter