Last Updated: Aug 06, 2019     Views: 124

Pictured: Glass with flaws.

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The Corning Museum of Glass online dictionary defines optical glass as “glass of extreme purity and with well-defined optical properties.”

Some of these properties include chemical stability and mechanical attributes, such as the hardness of the glass and scratch resistance (“About Mechanical Characteristics of Optical Glass,” 2012.)

When you look at optical glass, it is visually perfect and colorless, lacking any type of defects such as stones (pieces of unmelted glass), seeds (bubbles), or cords (unevenly mixed glass).

Contemporary Uses

Optical glass has been used, and is still used, to make lenses, glasses, and prisms. Currently, it is also used to make medical devices, works of glass art, and fiber optic cables.


You can read some of the history of optical fiber, Corning Glass Work’s contribution of fused silica, and how Alexander Graham Bell created an early fiber optics prototype using glass and sunshine in the All About Glass article “On a Thread of Glass: Optical Fibers for Communication.”

Optical glass is not easy to make as it requires that the glass be perfectly melted, mixed, and cooled. You can read about the breakthrough in optical glass creation, led by Physicist Charles DeVoe in the All About Glass article “Continuous Perfection: Optical-Quality Glass” (2011). Before DeVoe, only 10% of optical glass made was usable.

Further Reading

Want to learn more? Check out the Rakow Research Library to search the collection for information about optical glass.








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Please note: The Corning Museum of Glass is a non-profit, educational institute and, as such, cannot answer questions about rarity or value of your glass. For more information about appraisal services, see our curatorial FAQs.

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