While wave upon wave of smartglasses and face-based wearables crash on the shores of CES, traditional glasses really haven’t changed much over the hundreds of years we’ve been using them. The last innovation, arguably, was progressive multifocals that blended near and farsighted lenses — and that was back in the 1950s. It makes sense that autofocusing glasses maker IXI thinks it’s time to modernize glasses.

After recently announcing a 22-gram (0.7-ounce) prototype frame, the startup is here in Las Vegas to show off working prototypes of its lenses, a key component of its autofocus glasses, which could be a game-changer.

IXI’s glasses are designed for age-related farsightedness, a condition that affects many, if not most people over 45. They combine cameraless eye tracking with liquid crystal lenses that automatically activate when the glasses detect the user’s focus shifting. This means that, instead of having two separate prescriptions, as in multifocal or bifocal lenses, IXI’s lenses automatically switch between each prescription. Crucially — like most modern smartglasses — the frames themselves are lightweight and look like just another pair of normal glasses.

With a row of prototype frames and lenses laid out in front of him, CEO and co-founder Niko Eiden explained the technology, which can be separated into two parts. First, the IXI glasses track the movement of your eyes using a system of LEDs and photodiodes, dotted around the edges of where the lenses sit. The LEDs bounce invisible infrared light off the eyes and then measure the reflection, detecting the subtle movements of your eye and how both eyes converge when focusing on something close.

Using infrared with just a “handful of analog channels” takes far less power than the millions of pixels and 60-times-per-second processing required by camera-based systems. IXI’s system not only tracks eye movements, but also blinking and gaze direction, while consuming only 4 milliwatts of power.

Most of the technology, including memory, sensors, driving electronics and eye tracker, is in the front frame of the glasses and part of the arms closest to the hinge. The IXI prototype apparently uses batteries similar in size to those found in AirPods, which gives some sense of the size and weight of the tech being used. The charging port is integrated into the glasses’ left arm hinge. Naturally, this does mean they can’t be worn while charging. IXI says that a single charge should cover a whole day’s usage.

The prototype frames I saw this week appeared to be roughly the same weight as my traditional chunky specs. And while these are early iterations, IXI’s first frames wouldn’t look out of place in a lineup of spectacle options.

The team has also refined the nose pieces and glasses arms to accommodate different face shapes. Apparently, when testing expanded from Finland to the UK, British faces were “…different.” A little harsh when talking to me, a Brit.

Eiden pulled out some prototype lenses, made up of layers of liquid crystal and a transparent ITO (indium tin oxide) conductive layer. This combination is still incredibly thin, and it was amazing to watch the layers switch almost instantly into a prescription lens. It seemed almost magical. As they’re so thin, they can be easily integrated into lenses with existing prescriptions. It can also provide cylindrical correction for astigmatism too.

Autofocus lenses could eliminate the need for multiple pairs of glasses, such as bifocals and progressives. Even if the glasses were to run out of power, they’d still function as a pair of traditional specs with your standard prescription, just lacking the near-sighted boost. IXI’s sensor sensitivity can also offer insight into other health conditions, detect dry eyes, estimate attentiveness and, by tracking where you’re looking, even posture and neck movement. According to Eiden, blink rate changes with focus, daydreaming and anxiety, and all that generates data that can be shown in the companion app.

Hypothetically, the product could even potentially adapt prescriptions dynamically, going beyond the simple vision correction of Gen 1. For example, it could offer stronger corrections as your eyes get fatigued through the day.

IXI appears to be putting the pieces in place to make these glasses a reality. It still needs to obtain the necessary medical certifications in order to sell its glasses and get all the production pieces in place. It’s already partnered with Swiss lens-maker Optiswiss for manufacturing. Eiden says the final product will be positioned as a high-end luxury glasses option, selling through existing opticians. The company hopes to finally launch its first pair sometime next year.