Flint glass is combination of silicon dioxide (SiO2) with lead or potassium. It creates a relatively high refractive index and high degree of light dispersing power compared to other types of glass. Flint glasses are arbitrarily defined as having an Abbe number of 50 to 55 or less. Flint glasses have refractive indices ranging between 1.45 and 2.00.As a result, this blend of glass is characterized by its brilliance and luminosity. This property makes flint glass especially desirable in the production of lenses, optical instruments, and prisms. In modern flint glass, lead oxides are replaced with other metal oxides such as titanium dioxide and zirconium dioxide without significantly altering the optical properties of the glass.