Little more than a day after announcing it was adding Eye Control to Windows 10, Microsoft is letting Windows Insiders take the feature for a spin.

Eye Control is an accessibility-enhancing eye technology that started off three years ago as a One Week project. One Week is Microsoft's annual internal hackathon, and in 2014, the Eye Gaze Wheelchair team took the top prize for a system that enabled Steve Gleason, a former NFL player diagnosed with amyotrophic lateral sclerosis (ALS), to move his motorized wheelchair by simply glancing at a Surface tablet.

After three years of engaging the ALS community along with work done by the software giant's researchers and engineers, the technology is being made available to millions of Windows users.

Windows 10 build 16257, out now for members of the Windows Insider early-access program, features a beta of the new Eye Control feature as an accessibility option. Unlike most of the operating system's other accessibility settings, using Eye Control requires specialized hardware, not just an ordinary front-facing camera.

The experience requires a compatible eye tracker, like the Tobii Eye Tracker 4C, which unlocks access to the Windows operating system to be able to do the tasks one could previously accomplish with a physical mouse and keyboard," announced Dona Sarkar, a software engineer at Microsoft's Windows and Devices Group in a blog post. "We are starting by supporting the EN-US [English, United States] keyboard layout, and we are looking to expand to more keyboard layouts in the future."

Microsoft also plans to expand support to more eye trackers, including the Tobii Dynavox PCEye Mini, PCEyePlus, EyeMobile Plus and I-series, said Sarkar.

Addressing potential privacy concerns, the Eye Control settings pane assures users that their data is safe. "We don't save or share eye tracking data," reads a statement containing a link to Microsoft's privacy statement under feature's on-and-off toggle.

In addition to replicating mouse and keyboard functions, Eye Control supports shape-writing, wherein users focus on the first and last letter in a word and quickly glance at the letters in between. Windows' on-screen keyboard then generates predictive matches. Paired with the operating system's text-to-speech functionality, users can have phrases spoken aloud.

Eye Control is a work in progress, reminded Sarkar. The shape-writing function gets stuck on occasion and some interface elements can sometimes get in the way. Direct sunlight can also cause problems with the eye-tracking technology and changing lighting conditions may require a recalibration.

Also new in build 16257 is the company's first update to the Windows Console's default colors in 20 years. The command-line utility now supports full 24-bit RGB color, enabling new color schemes that improve legibility on today's displays, said Sarkar.

The Edge browser has been adorned with the company's Acrylic material, a part of the company's new Fluent Design System that lends depth and transparency to various interface elements with the aim of providing a more modern and polished look. The latest preview build also allows participants of both the Windows Insider and Office Insider programs to incorporate 3D objects into their Word, Excel and PowerPoint files.