What Causes the Screen Door Effect?
Displays like computer monitors, televisions, phones, and VR headsets all use pixels to display images. Each pixel is set to a specific color and brightness such that, when viewed together at an appropriate distance, the viewer perceives an unbroken image. If the viewer moves too close to a pixel-based display, they will eventually be able to make out the individual pixels and the space between the pixels. That’s what causes the screen door effect. Instead of perceiving the individual pixels as an unbroken image, it seems as if a fine mesh, like a screen door, has been placed between the image and the viewer. This is an illusion, because there is no actual mesh or grid present, and the viewer is just seeing the space between the pixels. The screen door effect is commonly associated with virtual reality, but you will also experience the same phenomenon when you sit too close to a television or hold a phone too close to your face if the resolution of the TV or phone screen is low enough.
What Does the Screen Door Effect Look Like?
If you have a screen door or a window screen in your home, you can approximate the screen door effect by looking at the world outside your home through the screen. Instead of the unbroken image that you’d see if the screen were removed, the world is obscured by a grid of black lines. The effect is stronger in lower resolution displays and can be very faint, or unnoticeable when the display resolution is very high. You can experience the same effect when viewing most monitors, TVs, and phones if you place your face close enough to the display. If you are able to see a black void between individual pixels when you place your face close to the screen, that’s the screen door effect. If you can’t, that means the resolution of the display is high enough that the pixels are so closely crowded together that your eyes can’t make out the individual pixels.
Does VR Still Have the Screen Door Effect?
Early VR headsets like the Oculus Rift were notorious for a very pronounced screen door effect because they made use of fairly low resolution displays placed in very close proximity to the viewer’s eyes. Most of the VR headsets on the market have some level of screen door effect, and the level to which you’ll experience the effect is directly dependent on the resolution of the headset. High-end headsets that include dual 4K screens or an 8K display are able to effectively remove the screen door effect, and the effect is very difficult to perceive in headsets built around 5K displays. Headsets with display resolutions lower than that are likely to exhibit some level of screen door effect.
How Do You Stop a Screen Door Effect?
To stop the screen door effect with a computer monitor, television, or phone screen, there are two options. The easiest option is to view the display from a sufficient distance so that your eyes aren’t able to make out the individual pixels. In most cases, that can be achieved by holding your phone further from your face or moving your couch further from your TV. The other option is to buy a new device with a high enough resolution that you can view it from the desired distance without being able to make out the individual pixels. For example, you can sit a lot closer to a 4K screen than a 1080p screen without experiencing the screen door effect. Apple Retina displays are specifically designed with this purpose in mind, but any display with a sufficiently high pixel density, or pixels per inch (PPI), will have the same effect. In virtual reality, the only way to stop the screen door effect is to buy a headset with a sufficiently high resolution. High-end 8K headsets that provide a separate 4K screen for each eye completely eradicate the screen door effect, but more affordable options get pretty close.
