 
 <prompt> How person fit reduce the refraction index of glass? Given the question wey dey before, write small tori wey get the answer. E fit be 1 - 20 sentences. <response>: Glass get di ability to bend, reflect, and send light dey go through geometrical optics, without scatter am. Dem dey use am for di production of lenses and windows. Common glass get refraction index wey dey around 1.5. Dis fit change if dem add low-density materials like boron, wey fit reduce di index of refraction (see crown glass), or increase am (reach as much as 1.8) with high-density materials like (classically) lead oxide (see flint glass and lead glass), or for modern uses, less toxic oxides of zirconium, titanium, or barium. Dis high-index glasses (wey people dey call "crystal" wen dem use am for glass containers) dey cause more chromatic dispersion of light, and people dey value dem for their diamond-like optical properties. 