Alternate Realities: How VR works

Ayleen Farnood
5 min readJan 24, 2019


On a gloomy day in the middle of Toronto, an old lady named Meike Muzzi sits on her hospital bed, in palliative care at Bridgepoint Health. In her mind, however, Muzzi is miles away in the Bahamas, enjoying the beautiful sunset over the bright blue ocean. Contrary to what one might think, she isn’t asleep nor off in the world of daydreams. Rather, she’s traveling all around the world with the help of virtual reality.

For those of you that don’t know, virtual reality is a three-dimensional, computer-generated environment that can be interacted with by a person. Within this virtual world, one is able to manipulate objects or perform certain actions as if they were actually there. With the ever-growing use of VR, we’ve now been able to see it used in so many different cases and industries. So, to see where this new craze with simulated environments began, let’s take a step back and learn how virtual reality actually works…

How exactly does VR work?

The main focus of virtual reality is to simulate the vision as well as possible in order to create an immersive 3D environment. Each VR headset puts up one or two screens in front of the user’s eyes in order to prevent any distractions from their surrounding environment (which is why most VR headsets nowadays look like a pair of bulky goggles). The video is sent to these screens either by an HDMI cable or, in the case of the Google Daydream and Samsung Gear VR, its already on the phone slotted into headset. Additionally, two autofocus lenses are generally placed between the screen and the eyes that adjust based on individual eye movement and positioning.

In order to ensure that their virtual reality experience is as immersive as possible, the frame rate of the game and the screen refresh rate must be a minimum of 60 fps and there should be a minimum 100° field of view. Essentially, the GPU must process a minimum of 60 images per second while the display must support movement of the eye and head. Among the major headsets available today, Vive and Rift both have 110-degree FOVs, Google Cardboard has 90, the GearVR has 96 and the new Google Daydream offers up to 120 degrees.

Without these features, the user may experience latency: too much of a time gap between their actions and the response from the screen. To avoid latency, there must be less than 20 milliseconds between the action and the response in order to trick the brain.

The user could also suffer from the issue of cybersickness if there is an inconsistency between the frame rate and refresh rate. Images can become distorted if the fps is more than the refresh rate, which can cause dizziness or feelings of nausea.

For ensuring that there is as much of an immersive experience as possible, sound effects and eye/head tracking are very important. All headsets have headphones and 3D sound effects which simulate noises or music which one might hear in the environment. Furthermore, eye and head tracking is ensured either through laser pointers, LED lights, or mobile sensors. With mobile sensors, accelerometers are used for 3D movement, gyroscopes for angular movement, and magnetometers for identifying the position of the user relative to Earth. However, in order to achieve very high accuracy, cameras and sensors would have to be installed in the room where the user would utilize the headset.

What can we do with VR?

Aside from gaming, virtual reality is being used in so many industries such as education, healthcare, space, etc. Here are just three of the examples of the various applications of this technology:


The healthcare industry has been a big adopter of virtual-reality tech. There have already been hospitals which use VR simulations with actual diagnostic images from CAT scans or ultrasounds to construct 3D models of a patient’s anatomy. These models can help surgeons determine the safest and most efficient way to locate tumours, place surgical incisions or practice difficult procedures ahead of time.

In addition, VR could also be used for rehabilitation. Stroke and brain injury victims across Europe can now use VR therapy created by MindMaze to regain motor and cognitive function faster than with traditional physical therapy. And these are not its only applications in this field, with other examples including the use of VR to reduce chronic pain, relax patients, and much more.


Businesses will be able to send their clients on virtual tours of houses and office space without ever needing to be there in person. VR has also been used to view both the interior and exterior of products so that consumers can see what they’re going to be purchasing. Lastly, communication and meetings have already began the shift from using video chats to full-on virtual conference rooms.


The U.S. military often uses virtual-reality simulators to train soldiers before they are deployed. Because VR is so immersive, it’s often times a really great simulation of what can happen in reality. The gamelike simulations allow teams to practice working together in realistically replicated environments before they have to use real-world tactical equipment.

Even though VR has already been around for a couple of years, it’s still an awesome technology and there’s been constant work on trying to revise and improve it to create as immersive of an experience as possible! After all, with so many applications in our real world, VR will definitely impact the way we live in our world today.

Make sure to stay tuned for more articles to see what virtual reality games I’m building right now!

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Ayleen Farnood

machine learning + brain-computer interface + fullstack dev! check out to learn more :)