In many contemporary living rooms, large TVs reign supreme; however, researchers suggest that investing in ultra-high-definition models may not be worthwhile.

Scientists from the University of Cambridge and Meta, the parent company of Facebook, discovered that in an average-sized living space, 4K or 8K screens offer no notable benefits compared to a similarly sized 2K screen typically found on computers and laptops. Essentially, there is no visible difference in image sharpness to the human eye.

“At a specific viewing distance, adding more pixels makes little difference; the human eye isn’t capable of detecting them, so I consider it a waste,” stated Dr. Maliha Ashraf, the study’s lead author from the University of Cambridge.

In an article published in Nature Communications, Ashraf and colleagues elaborate on measuring the visual resolution limits of the human eye, indicating that 20/20 vision allows detection of 60 pixels per degree (PPD), although many individuals with normal or corrected vision can see better than this.

“Basing display resolution solely on 20/20 vision underestimates what individuals can actually perceive,” Ashraf asserts. “That’s why we conducted direct measurements of the pixels people can identify.”

The research team set up a 27-inch 4K monitor in a mobile cage, allowing it to be adjusted closer or further from viewers. Eighteen participants with normal or corrected vision were shown two images at varying distances in random order. One image featured 1-pixel-wide vertical lines in colors such as black and white, red and green, or yellow and purple, while the other was a plain gray block. Participants were tasked with identifying the image containing the lines.

“If the lines are too thin or the screen resolution is excessive, the pattern appears as merely a gray image,” Ashraf explains. “We measured the points where individuals can barely discern differences. We referred to this as the resolution limit.”

Through their findings, researchers concluded that the human eye can perceive more detail than previously assumed, with a straight-on grayscale image averaging 94 PPD, red and green patterns averaging 89 PPD, and yellow and purple patterns at 53 PPD.

In a separate experiment, 12 participants viewed white text on a black background, or the reverse, from various distances and indicated when the text matched the sharpness of a clearly defined reference version.

“The resolution at which participants ceased to detect differences in text aligned with our observed results in line patterns,” Ashraf noted.

The research team shared a table featuring various screen sizes and viewing distances, along with the nearest standard resolution meeting or slightly exceeding most people’s visual limits.

“This means that if your setup falls within one of these parameters, upgrading to a higher resolution will not yield measurable benefits,” Ashraf remarked.

The team also offers a free online calculator that allows users to input their viewing distance, screen size, and resolution to see if their settings are within or below the human eye’s resolution limit. This helps users assess whether a higher resolution screen would enhance what they can see.

“For instance, if someone owns a 44-inch 4K TV and views it from about 8 feet away, they’re already seeing more detail than they can actually perceive. Upgrading to an 8K version of the same size won’t provide any sharper images,” Ashraf concluded.