Why Multiple Displays Are (Much) Better than VR Headsets

There is increasing interest in using “Virtual Reality” (VR) Headsets such as Meta’s “Quest”, HTC’s “Vive”, and Varjo’s “XR” for simulator-based training [1].

The idea: when you turn your head, movement is detected by “head-tracking” electronics in the VR Headset, and then what you see on the two small displays in front of your eyes (inside the VR Headset) changes accordingly.

Unfortunately, most people will experience cybersickness, “a form of motion sickness characterized by nausea, disorientation, and oculomotor strain” [1]. Other symptoms can include blurred vision, vertigo, dizziness, fatigue and headache [6], and the symptoms can begin within the first 45-60 seconds [1]. One recent study published this year about simulator-based training for heavy equipment noted that 80-95% of users experienced some level of discomfort and for a few participants, symptoms were so severe that they had to abandon their training [7]. 

Practically, cybersickness is due to two problems [2], [3].

Reduced Field of View

Our visual field of view is about 200 degrees left/right, and about 160 degrees up/down [5]. “Central” vision is what’s right in front of you, so everything else is “peripheral” vision. And that peripheral vision is especially important for performing psycho-motor tasks [5].

Consider an excavator loading a truck from a trench. In the real world, you rely on your central vision to follow the excavator’s bucket, but on your peripheral vision to guide bucket from the trench to the truck box. And that’s exactly what should also happen in the simulated world.

But with a VR Headset, your field of view is limited to seeing what’s directly in front of you, much like the “blinders” that prevent a racehorse from seeing side-to-side. For that reason, with a VR Headset, you must turn your head to “see” left /right and up/down. This, of course, makes it difficult, in the simulated world, to rely on peripheral vision to guide the bucket of the simulated excavator from the (simulated) trench to the (simulated) truck box.

Consider now a forklift at work in a warehouse. As you travel down the aisle, the loads on the racks to the left and right seem to move backwards as you move forwards (past them).

Well in the simulated world, because the VR Headset’s field of view is so limited, all that “motion” fills up your viewing angle, and “tells” your brain that your body should be moving too (when it’s not), and this “mismatch” also contributes to cybersickness. And the effect becomes more pronounced as you travel faster, making the objects around you seem to “move” faster.

Reduced Real-Time Interactivity

The second problem with using VR Headsets is the time delay between turning your head and “seeing” in the new direction, also called “lag” or “latency”, because off-the-shelf computers can’t “keep up” with typical head movements [6].  The fact is, your body will “notice” even a very small lag, and that contributes to cybersickness.

Here are the technical details: “frame rate” refers to the number of times, per second, that the head-tracking “notices” movement, the computational elements “decide” what to change now that you are looking in a new direction, performs lots of calculations associated with those changes, and finally “re-draw” what you see inside the VR Headset. To avoid cybersickness, the frame rate must be very high (at least 90 Hz, often 120 Hz), and that requires lots of computing horsepower.

For that reason, “stand-alone” VR Headset with a built-in computer still needs the “help” of an external computer via a cable or “tether” (wireless connections are too slow) for optimal performance [1].

Of course you can reduce the computing “load” to use just the onboard computer (and no “tether”) by making the simulation graphics and physics “cartoon-ish”, but that will greatly reduce the operator training help provided.

Practically, you can mitigate the time delay problem in two ways: first, by learning to turn your head s-l-o-w-l-y, and second, by training for just a few minutes at a time, and not every day [6]. Clearly, both “solutions” would greatly impact simulator-based training.

Why Multiple Displays are (much) Better for Training Simulation

In the real world, you can turn your head as quickly as you want and you always see something new, i.e. there is no “time delay”.

More importantly, when you look forwards, you see not just forwards but also left/right and up/down. And as previously indicated, because peripheral vision is key to operating heavy equipment, preserving that “natural” field of view is vital for real work and therefore for the simulator-based preparation.

Well with Simlog, you can set up three “big screen” displays in front of the simulator controls to provide a panoramic field of view of 180 degrees. (And when it’s important to turn your head to look backwards when moving backwards, just add another “big screen” display set up behind the simulator controls.)

Fortunately, the growing popularity of home entertainment systems has brought the price of off-the-shelf HD (UHD, and now 4K) “flat screen” TVs within the reach of every budget, even as the size of popular models continues to increase to 65”, 75″ or more. Indeed, bigger displays “fill up” more of your field of view, making the simulation experience more “immersive” to thereby improve the operator training help.

Today, you’ll find that the price of four “big screen” displays can often be less than the price of a single VR Headset.

Six More Reasons Why Multiple Displays are (much) Better

At Simlog, we’ve identified six additional limitations associated with VR Headsets.

1. Wearing a VR Headset limits what you see to just the simulated world. For this reason, it can be difficult, for example, to reach for a forklift lever with your right hand (in the real world) because you cannot “see” the lever or your hand. More expensive VR Headsets overcome this problem by adding cameras to “superimpose” what the cameras “see” on top of the simulated world to create “augmented reality”, at added cost. Of course, this also means that you will “notice” everything the cameras “see”, so not just the lever you want to move, but everything around the lever too, and that will necessarily reduce the sense of “immersion” in the simulated world.
2. VR Headsets are uncomfortable to wear for the extended periods of time required for simulator-based training, because of the weight on your head and the display fitting tightly over your eyes (to block out the real world around you).
3. If you wear glasses, you may have problems “fitting” the VR Headset on top of them. Indeed, according to one recent study [7], 40% of the participants who normally wore glasses (to correct vision problems) chose to remove them when using the VR Headset. And not seeing properly, of course, greatly reduces the value of the simulator-based training.
4. When sharing a single simulator “station” among many trainees, the VR Headset must be adjusted each time (everyone’s head is different), and that means extra wear-and-tear that can quickly lead to damage.
5. As previously indicated, even “stand-alone” VR Headsets must be typically connected to an external computer via a tether for optimal performance, and that tether “gets in the way” when you move your head.
6. When wearing a VR Headset, only you can “see” what’s going on. So, if you want a second trainee to learn by watching the first trainee, or your Instructor to monitor the simulated work, you will need to add a conventional display at additional cost.

Clearly, using multiple displays has none of these limitations.

The Bottom Line

Because what you see is so important, multiple “big screen” displays will always deliver superior support for hour-after-hour simulator-based training.

The fact is, today’s VR Headsets present too many limitations for “industrial strength” simulator-based training. And although the technology is improving (slowly), off-the-shelf “flat screen” TVs are increasing in size much faster, and at prices that continue to fall (even as the price of high-end VR Headsets continues to rise). Practically, this means that “filling up” your field of view with multiple displays is increasingly affordable.

One final note.  A recent review of the scientific research about using VR Headsets for education and training [4] concluded that when developing the psycho-motor skills needed for operating heavy equipment, VR Headsets have

… no advantage [compared to multiple displays] and in some cases can even be counter-productive because of widespread cybersickness, technological challenges, or because the VR experience distracted from the learning task.

To comment on anything you read here, please write to “info@simlog.com” with “blog” in the Subject, to direct your message to me.

Other blog posts about Simulation Technology

References

[1] “Assessing Virtual Reality Head-Mounted Display-Induced Cybersickness in Simulated Maritime Dynamic Environments”, Proceedings of the I/ITSEC Conference, Paper No. 25213, 2025.

[2] “The Science of Simulation”, MS&T – The International Defense Training Journal, Halldale Group, June 2019, 

[3] “The Virtual Reality Head-Mounted Display Oculus Rift Induces Motion Sickness”, Experimental Brain Research, Volume 235, Issue 3, 2017.

[4] “A Review of the Use of Virtual Reality Head-Mounted Displays in Education and Training”, Education and Information Technologies, Volume 23, 2018.

[5] R. Magill, D. Anderson, Motor Learning and Control: Concepts and Applications, McGraw-Hill, 12^th Edition, 2021.

[6] “Cybersickness Considerations for Curricula using Virtual Reality Training Systems”, Proceedings of the I/ITSEC Conference, Paper No. 23331, 2023.

[7] “A User-Centered Evaluation of a VR MHD-Based Harvester Training Simulator”, Multimodal Technologies and Interaction, Volume 10, Issue 15, 2026.