Corning, a key Apple supplier ever since the introduction of the original iPhone 10 years ago, has been working on dedicated glass wafers for augmented reality (AR) glasses and mixed reality headsets. This work could put the company in a position to become an essential partner when Apple begins the production of its reported AR headset.

Bloomberg reported earlier this week that Apple is looking to build its own AR headset by 2019, in time to ship it as a commercial product by 2020. Apple has not commented on reports that it is working on such a device.

However, Apple CEO Tim Cook has repeatedly expressed enthusiasm for augmented reality. “I view AR as profound,” he said during a recent earnings call. “I think Apple is in a really unique position to lead in this area.”

Corning has been supplying Apple with display glass ever since the introduction of the original iPhone in 2007. Among tech enthusiasts, the company is best known for its Gorilla Glass, which is also being used by phone makers like Samsung, HTC, and Huawei, among others.

However, the company has also for some time worked on specialized glass for AR glasses and headsets, telling prospective customers in a data sheet: “For ‘see-through’ consumer electronic applications, Corning’s solutions deliver outstanding field of view, image quality and definition (sharpness, contrast and low chromatic aberrations).” Corning also recently published a YouTube video touting its AR chops.

Corning’s work in this field isn’t just notable because of the two companies’ existing iPhone working relationship. Apple also invested $200 million in Corning in May as part of a $1 billion commitment to strengthen U.S. manufacturing. The two companies said at the time that the investment was intended to support Corning’s research and development as well as capital equipment needs and glass processing capabilities.

Apple and Corning didn’t respond to a request for comment on whether these research and development efforts will also include augmented reality glass products.