Mind & Behaviour   ·   Synthesis

Note on status: this piece carries a Synthesis tag. The finding that certain patterns in the built environment strain vision belongs to the vision scientists cited below, not to me. The step from that finding to ordinary daily tiredness is my own hypothesis, not a reported finding; the “Where This Argument Is Solid, and Where It Isn’t” section states exactly where the research ends and the hypothesis begins.

A Day Made of Straight Lines

Think about an ordinary day. You wake up in a rectangular room. You drive down a straight road, between straight buildings, glancing at a straight dashboard. You sit in an office and stare at a screen — flat, close, unmoving — for hours. Then you go home to more rectangles. Nearly everything our eyes touch is a straight line, a grid, or a flat surface.

So here’s a question worth asking directly: if so much of what we look at is flat, straight, and repeating, could that alone be part of why modern life feels tiring — separately from the reasons we already know about, like poor sleep or too much sitting?

What We Already Know About Screens and Blinking

There’s a real, measurable cost to part of this picture. We blink far less while looking at screens. A 1993 letter to the New England Journal of Medicine by Tsubota and Nakamori reported blink rates falling sharply across conditions in a study of 104 office workers: about 22 blinks a minute at rest, 10 while reading a book, and 7 while viewing a screen [2]. It’s worth noting this was a short clinical correspondence, not a full peer-reviewed study. Even so, the finding has held up well, and independent, more rigorous work has since confirmed the broader pattern of screens reducing blink rate [3]. Fewer blinks means drier, more strained eyes.

Honest caveat: later researchers, including vision scientist Mark Rosenfield’s lab, found that when they carefully controlled for how mentally demanding a task was, some of this blink-rate drop seemed tied to how hard the brain is working, not the screen itself [3]. So it may be less “screens are uniquely bad” and more “hard mental focus, on any surface, reduces blinking.”

That’s one documented cost of the linear, screen-heavy life most of us live. But it doesn’t yet explain why time spent in nature feels like it undoes something that screens and walls don’t.

Why Nature Calms Us

Most people already know this experience intuitively. A short walk near trees, open sky, or water often feels different from an hour spent inside a rigidly structured room. Now compare a forest, a coastline, or a cloud to a city grid. Almost nothing in nature is straight, and almost nothing repeats exactly. Branches fork unevenly. Coastlines bend without a pattern you could draw with a ruler. This kind of shape — irregular, but not random — is called a fractal (see Glossary).

Focused attention runs down like a battery, and nature seems to recharge it. This is a respected idea in psychology called Attention Restoration Theory, developed by researchers Rachel and Stephen Kaplan [4]. The kind of effortful, directed focus we use at work, in traffic, or on a screen drains something in the brain. Natural settings — without demanding anything of that same focus — appear to let it recover.

This part deserves more space, because it’s the closest thing this piece has to a proven answer, not just a hypothesis. Physicist Richard Taylor and colleagues have spent years studying what they call “fractal fluency” [5] — the idea that human vision evolved around exactly the kind of medium-complexity irregular patterns found in nature (tree branches, clouds, waves), and processes them with unusual ease. In plain terms: natural patterns aren’t just pleasant to look at — they seem to be patterns our visual system is already built to handle smoothly, the way a familiar road is easier to drive than an unfamiliar one.

That ease shows up as a measurable change in the brain, not just a reported feeling. A 2022 study (Grassini and colleagues) recorded people’s brain activity while they watched nature videos versus city videos, using a technique that picks up the brain’s electrical activity from the scalp [6]. Nature videos reliably produced calmer, more relaxed brain-wave patterns than city scenes did — the same kind of signal researchers associate with rest and recovery, not just a subjective sense of liking a view more. This is one of the few parts of this piece that has been directly tested and shown to hold.

The Idea I’m Proposing

Here’s the connecting idea: a visual diet made almost entirely of straight lines and grids may be quietly wearing us down in a specific way — separate from the well-known causes of tiredness — and we’ve missed it because it’s invisible. Nobody complains “my eyes are tired of rectangles” the way they complain about poor sleep.

Part of this, it turns out, has already been tested — by vision scientists rather than by the people who study tiredness. Arnold Wilkins at the University of Essex has spent four decades showing that some patterns cause measurable visual discomfort regardless of what they depict: stripes and repeating grids at certain spacings can bring on headaches and, in susceptible people, seizures [8]. Working with Olivier Penacchio, he has shown why. Natural scenes share a statistical signature — roughly the same amount of contrast at every scale — and the visual cortex is tuned to process images with that signature economically. Images that depart from it, which includes much of the built environment, make the cortex work harder, and people rate them as uncomfortable [9]. A 2017 study measured oxygen use in the visual cortex while people looked at urban and rural scenes: the urban scenes cost more [10]. Wilkins’ group has since written directly about what this means for buildings and cities [11].

So the idea this piece adds is narrower than it first looks. Not that geometry can strain vision — that is established. Rather, that an ordinary day’s worth of it accumulates into the general, low-grade tiredness most of us put down to other causes. That step has not been tested.

Why This Might Matter, If True

The tips below are low-cost either way — nobody is harmed by looking at a tree for 20 seconds if the hypothesis turns out to be wrong. Worth treating as a personal experiment rather than a proven fix:

• Every hour or so, rest your eyes on something irregular for 20–30 seconds — a tree, clouds, or even a photo of one.
• Step outside briefly during the day, instead of another screen or corridor.
• For a few days, rate your eye comfort and mental freshness (1–10) each evening, and note time spent looking at natural scenes — then compare the days.

That won’t prove the theory. But it costs nothing, takes seconds, and might be the easiest fix hiding in plain sight: give your eyes something they weren’t built to ignore.

Where This Argument Is Solid, and Where It Isn’t

Modern visual life being overwhelmingly geometric is simply observable. That some geometric patterns strain the visual system, and that the visual cortex works harder on urban scenes than on natural ones, is established [8–10]. That an ordinary day of such patterns accumulates into the everyday tiredness most people attribute to other causes — the step from laboratory discomfort to daily fatigue — is the hypothesis, and no study has tested it. That natural, irregular patterns help offset this is partly supported by the calming effects described above, though not proven to work through the exact channel described here.

The asymmetry matters: we know nature calms us. We don’t know whether missing it tires us, or whether it just means we miss out on a lift we’d otherwise get. This piece bets on the first, and says so plainly.

The Bigger Picture

This piece proposes one additional factor for investigation. It sits alongside causes already well established in the literature — sleep, posture, screen brightness and flicker, and sustained cognitive load. Reviews of digital eye strain consistently describe the condition as multifactorial, with researchers still working out how these mechanisms interact [7]. This adds one more candidate to that list; it does not argue the established ones are wrong.

Modern humans carefully manage their food diet, their information diet [1]. Perhaps it’s time to manage our visual diet too.

If this hypothesis is worth taking seriously, it’s worth testing properly. A few starting points for anyone who wants to:

• Compare visual fatigue markers between fractal-rich and rectilinear environments, holding lighting, brightness, and task type constant.
• Track eye-movement patterns across different geometric settings to see whether straight-line environments demand measurably different visual effort.
• Test whether brief exposure to natural fractal patterns produces a measurable drop in subjective or physiological fatigue, not just a reported preference.
• Explore whether fractal-inspired interior or workspace design changes perceived visual comfort over time.

Conclusion

In short: modern eyes take in far more straight lines and grids than at almost any point in human history. Whether that specific pattern adds its own kind of fatigue, separate from the causes we already know, is not yet proven — but it costs little to test, and even less to try.

The labels change — screen fatigue, digital eye strain, burnout — but the underlying question stays the same: what, exactly, are we asking our eyes to carry all day, and what would it cost to give them something else to look at?

Glossary

• Fractal — a pattern that repeats itself at different sizes in an irregular, non-repeating way (e.g., how a tree’s branches split into smaller branches that look similar in shape to the whole tree). Common in nature; rare in built environments.
• Fractal fluency — a research model (Richard Taylor and colleagues) proposing that human vision has adapted to process natural, medium-complexity fractal patterns with particular ease.
• Attention Restoration Theory (ART) — a psychology theory (Rachel and Stephen Kaplan) proposing that directed, effortful attention is a limited mental resource that depletes with use and recovers especially well in natural settings.
• Brain-wave / EEG activity — the brain’s electrical activity, measurable from the scalp; certain patterns are associated with calmer, more relaxed mental states.
• Synthesis (tag) — an editorial tag marking a claim as the author’s own connective idea or hypothesis, not a reported finding from the cited sources.

Citations

[1] Johnson, C. (2012). The information diet: A case for conscious consumption. O’Reilly Media.

[2] Tsubota, K., & Nakamori, K. (1993). Dry eyes and video display terminals [letter]. New England Journal of Medicine, 328(8), 584. https://doi.org/10.1056/NEJM199302253280817

[3] Chu, C. A., Rosenfield, M., & Portello, J. K. (2014). Blink patterns: Reading from a computer screen versus hard copy. Ophthalmic and Physiological Optics, 34(5), 546–550.

[4] Kaplan, R., & Kaplan, S. (1989). The experience of nature: A psychological perspective. Cambridge University Press.

[5] Taylor, R. P., Viengkham, C., Smith, J. H., Rowland, C., Moslehi, S., Stadlober, S., Lesjak, A., Lesjak, M., & Spehar, B. (2024). Fractal fluency: Processing of fractal stimuli across sight, sound, and touch. In Fractal Geometry of the Brain II. Springer.

[6] Grassini, S., Revonsuo, A., Castellotti, S., Petrizzo, I., Benedetti, V., & Koivisto, M. (2022). Watching nature videos promotes physiological restoration: Evidence from the modulation of alpha waves in electroencephalography. Frontiers in Psychology, 13, 871143.

[7] Barata, M. J., Aguiar, P., Grzybowski, A., Moreira-Rosário, A., & Lança, C. (2025). A review of digital eye strain: Binocular vision anomalies, ocular surface changes, and the need for objective assessment. Journal of Eye Movement Research, 18(5), 39.

[8] Wilkins, A. J., Nimmo-Smith, I., Tait, A., McManus, C., Della Sala, S., Tilley, A., Arnold, K., Barrie, M., & Scott, S. (1984). A neurological basis for visual discomfort. Brain, 107(4), 989–1017.

[9] Penacchio, O., & Wilkins, A. J. (2015). Visual discomfort and the spatial distribution of Fourier energy. Vision Research, 108, 1–7.

[10] Le, A. T. D., Payne, J., Clarke, C., Kelly, M. A., Prudenziati, F., Armsby, E., Penacchio, O., & Wilkins, A. J. (2017). Discomfort from urban scenes: Metabolic consequences. Landscape and Urban Planning, 160, 61–68.

[11] Wilkins, A., Penacchio, O., & Leonards, U. (2018). The built environment and its patterns: A view from the vision sciences. Journal of Sustainable Design and Applied Research, 6(1).