Apple’s revealing that its new Vision Pro mixed reality headset is outfitted with displays that have a 90Hz refresh rate. The new detail comes in an online WWDC session for developers where Apple shares how 2D video and stereoscopic 3D video work in the headset.

It’s common to see 90 to 120Hz screens on tech from smartphones to PC gaming monitors, as it provides quicker responsiveness and smoother motion than slower displays. Apple has generally used 60Hz displays on everything it makes other than some of its “pro” devices like the iPad Pro and MacBook Pro that have 120Hz ProMotion displays. For a screen directly in front of your eyes, that added speed will make a big difference.

The Vision Pro screens can also automatically switch to 96Hz, which is designed for playback of videos that are running at 24 frames per second, like most movies. There’s also support for both standard and high dynamic range (HDR) content.

As UploadVR points out, 24 multiplies evenly into 96, keeping the frames of both the playback video and the displays at a consistent rate. If the displays were running at 90Hz with a 24fps video, it would look like frames are dropping or lagging.

The WWDC session video continues to talk about 3D video support and how content providers can use stereoscopic video, where left and right eye frames are merged instead of having an independent video view per eye. This matches how 3D movies work in theaters, where if you remove the provided 3D glasses, you’ll see an odd 2D image with slightly garbled perspectives.

Another cool detail is that video can be encoded using both MP4 or HEVC — which is the default codec used when recording video on iPhones. Specific to the headset, 3D videos can be recorded in multiview HEVC to support stereoscopic frames.

In our hands-on with the Vision Pro, we noted the device is the Retina display moment for headsets. Part of that holds true due to Apple’s inclusion of pixel-dense MicroOLED displays that are near 4K for each eye — but now, it’s clear that the high refresh rates really helped with the experience. And another WWDC session video explains how developers can keep smooth interactions by adjusting their app’s input response time below 8ms.

The Vision Pro is one of Apple’s most experimental pieces of hardware to date, and as a result, the company hasn’t published a clear technical specification for it like it normally does for new releases. But as WWDC continues through Friday, we might run into more surprises — or we’ll just have to wait until we get closer to the device’s early 2024 release.