The exact composition of optical glass depends on its intended use and desired optical properties, such as refractive index, dispersion, and transmission. The glass is carefully formulated and refined to ensure that it has a high degree of clarity and uniformity, as even small impurities or variations in composition can cause distortions or other optical defects.
Optical glass is used in a wide range of applications, including telescopes, microscopes, cameras, and eyeglasses. It is also used in many industrial and scientific applications, such as laser optics, fiber optic communication systems, and spectroscopy.