The Importance of the VR Refresh Rate: Everything You Need To Know

Virtual technology is taking the world by storm, and more users than ever are embracing this form of entertainment because they are eager to find out what it’s like to be fully immersed in a virtual world. But what are the ingredients of a convincing VR experience? Among other things, the VR refresh rate is one of the vital components.

In this article, we’ll explain what refresh rate is in VR, how it works, and in what way it improves the virtual reality experience.

Why Is the Refresh Rate Important for VR? 

The VR industry is rapidly expanding. Data shows there are around 171 million VR users globally. This is the result of years of research efforts to make virtual reality worlds seem more real and engaging.

We can also notice numerous technological advances in the augmented reality industry, where most active users are 34 or younger. But how did we manage to make it so realistic and immersive? One of the main reasons is the increased refresh rate. 

When talking about the VR headset refresh rate, we’re talking about the specific number of times the image is refreshed per second. Typically, the refresh rate should be around 90 Hz, meaning the image is refreshed 90 times per second. 

In other words, the refresh rate has to do with how many frames the headset can produce per second. The slower the refresh rate of the VR is, the worse your experience with it will be, as the action will feel laggy, choppy, and less realistic.

Unlike standard computer graphics, which aren’t as affected by low fps, in VR, you might feel nausea as poor refresh rates will produce images that are not as natural-looking as those from the real world. 

VR refresh and morning sickness often go hand in hand. Apart from it, you might face vertigo and disorientation because your eyes won’t be able to keep up with the images properly. That’s why the refresh rate should be the first thing you should look for when browsing for a new VR. 

Even though the images flicker in a VR setting, we can see them normally when using a headset with a high refresh rate due to the persistence of vision - a phenomenon that helps us perceive images for a longer amount of time than the stimulus lasts. Therefore, this is a factor of paramount significance in VR if you want a fully immersive experience. 

Higher refresh rates and frame rates of VR headsets will also mean that you’ll need more processing power to run them properly, and their price will likely be higher, too. Although the optimal refresh rate is 90 Hz, the highest refresh rates for VR currently go from 120 Hz to 144 Hz. 

Still, even if the refresh rate is lower, it doesn’t mean the target audience will reject it. Oculus Quest had a refresh rate of 72 Hz, but due to the low persistence OLED display, it was well received because it reduced motion blur and latency. 

Refresh Rate, Frame Rate, and VR Presence

The monitor’s refresh rate indicates the maximum number of fresh images it can show in one second, but without actual content, that doesn’t mean anything. Your video game must render 60 frames each second to fully utilize a 60 Hz screen. Anything less, and you might get weird artifacts on screen unless you use VSync.

Regarding the frame rate in VR, it’s like a temporal resolution that deals with the details in a particular image. At 60 frames per second, you’re getting 60 updates of the image per second. Anything outside of those is invisible to us in VR. With an improved frame rate, you won’t only improve the visual aspect, but the entire interaction within the VR game will feel faster and more natural.

So, this is the key difference between the frame rate and the refresh rate. The VR frame rate shows the number of separate images generated per second, while the refresh rate refers to the total number of times an image can be refreshed on screen per second. Both are very important for a smooth and lifelike VR experience.

But what is a VR presence? Since we perceive reality as the flow of sensory information and our vision is analog, we don’t have separate chopped images as we can see in computer games. 

Therefore, VR presence is essential for developers who want to deliver the most realistic sensations possible. The point is to trick your brain into thinking that you’re not playing a game and are, in fact, in a real-seeming, if virtual, world. For presence to happen, certain aspects must be taken care of first.

For achieving optimal VR presence, latency must also be at a specific level. That is, at most, 50 ms and ideally less than 20 ms. 

The horizontal VR field of view should be at least 90 degrees wide since our own vision is around 180 degrees. In other words, while not ideal, you’ll still achieve VR presence if you get a FOV of 90-plus degrees. In the following paragraphs, we’ll learn more about field of view and latency. 

The Importance of FOV

In virtual reality, the field of view is a term that refers to how much a user can see around them at once. The wider the FOV, the more a user can see and thus feel more immersed in the action. We measure the field of view’s height, width, and even depth. 

When you’re using a VR system of a lower quality, your field of view is typically more confined, and it’s as if you’re looking through a paper tube, with most of the surroundings not visible. Better VR models have a wider field of view range, but even the best of them still don’t offer a field of view that will provide complete immersion. 

It’s quite challenging to improve the VR field of view because many things need to be taken into consideration, and all of these aspects affect one another. Specifically, if the depth of the field view is increased, the lenses must be thinner, but then you’ll have to decrease the width and the height. Still, the industry is actively working toward a solution. 

Latency: What’s the Perfect Number?

Apart from the refresh rate, frame rate, and field of view, another term we need to tackle when talking about the VR experience is latency. 

In simple terms, latency refers to the delay between action and reaction, and having low latency is essential for both AR and VR headsets. VR headsets need to show every change on the screen right away, and if there is any delay, you won’t be able to enjoy the experience fully, as your brain will reject the legitimacy of the virtual surroundings. The motion sickness we’ve mentioned before can also be caused by high latency. 

As mentioned, the recommended refresh rate for VR should be at most 20 milliseconds, and must not exceed 50 milliseconds. Some of the best competitors on the market, such as Oculus Quest and HTC Vive, have a latency of 20 and 30-40 milliseconds, respectively. In that sense, Oculus Quest will provide you with a great VR experience, while the users of HTC Vive will notice the delay. 

The main task of VR and AR systems is to trick the brain into believing that we’re taking part in an almost real world, and if there’s high latency, our brain will immediately detect it, ruining the immersion of the whole experience. 

Bottom Line 

Virtual reality’s history dates back decades, but real, tangible improvements have only been happening in the past 10 years or so. However, the work is far from over, and developers need to work on many things to provide a better experience for VR users. The refresh rate is one of those aspects necessary for fully immersive gaming or other VR activities. 

We hope that our article has shed some light on the importance of VR refresh rates and helped you choose your next VR headset.