From Pools to Pixels: A Short History of Seeing Through Things

If you’ve ever caught yourself staring into a fountain, mesmerized by the way light scatters on the ripples, you’ve tapped into a fascination as old as humanity itself. For thousands of years, we’ve been bending, blurring, and playing with light – sometimes to reveal, sometimes to hide. And whether we’re talking about cathedral windows, mid-century glass blocks, or Apple’s upcoming update to iOS, the story is the same: transparency and distortion are one of design’s favorite magic tricks.

What’s striking is how these two ideas – letting you see while not quite letting you see – show up across centuries and across materials. The tools change, from still water and electrochromic smart glass to the fog on the shower door and pixels on your phone screen, but the effect on us stays familiar. It changes how we feel in a space. It changes what we notice. And it always, always draws you in.

Reflections in Stone and Water

Long before anyone made glass, our ancestors were already experimenting with transparency. Pools of still water were nature’s first mirrors, doubling the drama of temple courtyards and making an imperial walkway or hand-carved colonnade seem taller, grander and more alive. The Romans went a step further, building impluviums – an ingenious task on rainwater storage that didn’t just keep a building supplied, but bounced sunlight into its rooms and across its walls. It wasn’t just engineering; it was mood-setting. Philips Hue, anyone?

But of course, that water didn’t just reflect that light – it distorted it. If you’ve ever dunked your hand in a pool and marveled at the weird angle it appear at on the other side of the watery veil, then you’ve seen the first version of optical design. The ancients noticed this phenomenon too, using water-filled spheres to magnify wounds or tiny writing - in the process laying the groundwork for lenses.

By the time the Romans began installing glass windows in their wealthiest villas, the pattern was clear – both literally and figuratively. These panes were cloudy, wavy, and very much imperfect. They brought light in, kept weather out, and turned the view beyond into soft silhouettes. Glass was never just about vision. From the very beginning, it was all about atmosphere.

Stained Light and Curved Mirrors

Fast-forward to the Gothic cathedrals of medieval Europe, where sunlight streamed through walls of richly colored glass. Those windows weren’t about letting you see the street outside – they were about making you feel something inside. Deep reds, cobalt blues, fractured sunlight shifting with the hours – it was immersive, transportive, and just a little bit mysterious. Even in today’s busiest, loudest cities, a cathedral remains a sanctuary of remarkable quiet – the soft echo of footsteps, the coolness of stone under your fingertips – a stillness that heightens its pull and lets the resplendence of the stained glass take center stage. No matter your faith, it’s almost impossible not to feel something at a deep, human level when faced with such a carefully controlled sensory environment – a masterclass in mood-setting that has endured for centuries.

Elsewhere, glass became more personal. Small panes of something called crown-glass warped views into funhouse patterns. Early spectacles magnified cramped lettering for tired monks, transforming a blur into a crisp line of script. And then came mirrors – first flat, then curved – offering new, playful distortions. A convex “fish-eye” mirror could shrink an entire banquet hall into a shimmering, warped circle, much like a wide-angle camera lens does now. Even back then, designers were learning that distortion could be delightful – and it could be controlled.

Glass Meets the Machine Age

Then came the Industrial Revolution, and it blew the possibilities wide open. The Crystal Palace in London – basically a cathedral of iron and glass – showed the world what could happen when glass stopped being a precious rarity and started real use as a building material

But while the modernists chased perfect clarity and purity, others embraced texture. Pressed and patterned glass refracted sunlight deep into offices, making workspaces feel less like cramped boxes and more like stage sets for daily life. Louis Comfort Tiffany went even further, creating opalescent glass that shimmered like oil on water. These weren’t windows for looking through – they were windows for looking at, each piece glowing and shifting uniquely as you moved.

And then there were glass blocks – a personal favorite of mine I must admit - creating thick, glowing walls of light that made homes and storefronts look simultaneously futuristic and private. Stand inside and the world outside dissolved into abstract shapes, yet daylight still poured in. It’s a trick we’ve never really stopped loving, even if now it’s more likely to show up as a frosted blur behind a smartphone notification.

Privacy in Plain Sight

Mid-century designers leaned into the ability of glass to divide without fully severing. Fluted panels, sandblasted doors, even Japanese shōji screens – each allowed light to pass while softening whatever was beyond. With these, you could see enough to sense movement and space, but never enough to allow for complete clarity. (Today’s light-filtering blinds achieve much of the same effect - no travel to Tokyo or MCM price-tag required.)

And once again, this wasn’t just about privacy. It was about mood and atmosphere – about shaping how a space felt. A streaked silhouette through reeded glass made a room feel bigger and more intriguing. A shōji screen’s glow could make an interior seem calmer, almost weightless. The idea was simple: soften the edges, and you soften the experience. Ask subconscious questions about what lies beyond the partition, and you open up the imagination to the lived experience of that moment as a whole.

Even in product design, transparency was up for debate. Vintage acrylic watch crystals warped the numbers at the dial’s edge, while sapphire glass gave a distortion-free view. Some preferred the perfection, others missed the warmth of imperfection - and it’s a debate that rages on hotly to this day. Even outside of the watch-enthusiast forums, it’s the exact same conversation UI designers have about flat versus textured interfaces, with the expected cyclical trends and fiery discourse.

From Material to Metaphor

By the early 2000s, glass wasn’t just something you looked through – it was something you looked at on-screen. Apple’s Mac OS X Aqua interface made buttons feel like little blue droplets of liquid. Microsoft’s Aero Glass gave desktop windows a frosted-pane effect. And iOS 7’s frosted overlays and parallax effect added depth and context to an otherwise flat design world, allowing you to sense the home screen lurking just beyond the blur.

As with all good design, this wasn’t decoration for its own sake. It was functional. A semi-transparent panel kept you oriented in a digital space, the same way a glass partition keeps you oriented in a physical one. And because it borrowed directly from our physical experiences – frosted glass, textured panes, refracted light – it felt natural, it felt familiar, and it felt intuitive.

Following the era of “skeuomorphism” – a term that rose to prominence with the iPhone’s launch for its digital imitations of real-world textures – the early 2020s brought a new addition to the design lexicon: “glassmorphism.” This style layered translucent panels with gentle motion, soft blurs, highlights and shadows, evoking the overall look and feel of frosted or textured glass. Much like the wavy panes in an old shopfront or the fluted partitions of mid-century interiors, it hinted at what lay beyond while softening it into something more atmospheric. It was a clear break from the spotless, flat look that had ruled for years, swinging back toward something you could almost imagine reaching out and touching. And in the case of touchscreens, you actually would.

Liquid Glass and the Next Leap

Now we find ourselves on the cusp of Apple’s Liquid Glass era. Announced in June (2025), it’s their most ambitious take yet on transparency in UI. Thanks to major increases in processing power, UI elements behave like more like living material than ever before – reflecting and refracting their surroundings in real time. Scroll beneath a Liquid Glass sidebar and watch the background warp as though you’re peering through rippled antique glass. Move your device and light appears to glint and shift as if it were bouncing off a real surface.

It’s a feat of GPU rendering, sure, but it’s also a direct descendant of everything that’s come before – from Roman bathhouse windows to Tiffany lamps. Apple’s designers have even admitted the historical inspiration. By mimicking effects we live amongst in the physical world, they tap into our collective and individual design memory. The result is a UI that feels less like navigating clunky software and more like handling a natural object.

Why We Keep Coming Back to Transparency

Look across the timeline and you see the same repeating impulses. We let light in but keep detail out. We sharpen the view when focus matters, and blur it again to create mystery, mood or calm. We use distortion to add joy, mood, or emphasis. And we keep borrowing from the physical realm to inform the digital, because our brains already know how to read those cues and process what’s going on.

Because the truth is that transparency in design is rarely, if ever, about pure vision. It’s about control – of light, of focus, of emotion. Whether you’re behind a cathedral window, a shimmering glass wall, or a smartphone’s lock screen, you’re seeing the result of centuries of experimentation. Designers have always known that the space between fully clear and fully opaque is where the magic happens.

And that’s why, no matter how advanced our tech gets, the next big thing will probably still look an awful lot like glass.