At IXI, our science team spends its days exploring the challenges of human vision: challenges most people only notice when they start to experience problems. We sat down with Bioinstrumentation Fellow Juha Virtanen, Senior UX Researcher and Optometrist Tanja Lehti, and Researcher Sallamari Mehtälä to unpack six concepts that shape how we see, and how we design our lenses.

1. Worsening eyesight: Why vision changes over time

For many people, declining eyesight feels like a mystery. One year, you are reading a book without trouble, the next you find yourself holding it farther away. A common myth suggests that glasses are to blame, claiming they weaken the eyes or make them lazy. In reality, glasses do not change how your eyes work. They simply reveal how much correction your vision already needs.

So why does eyesight change over time? Biology is one answer. As we age, the inner structures of the eye naturally shift. The lens, which in youth flexes to bring things into focus, gradually loses its flexibility. Lifestyle is another factor. “Our visual system evolved for a world where we constantly switched between far horizons and nearby tasks. Today, we spend much of our time locked into one range, staring at screens and books up close. That constant demand places stress on the eye’s focusing system and can even leave it temporarily stuck in near vision, a state known as pseudomyopia.” Tanja continues.

These broad influences help explain why our vision changes, but most people's visual challenges typically stem from a few well-known conditions. In the chapters ahead, we’ll unpack each of them, show how they play out in everyday life, and explore how adaptive optics is opening new possibilities — bringing vision correction closer to the natural adaptability of the human eye.

2. Myopia - The alarming future of nearsightedness

Myopia, or “nearsightedness”, makes distant objects blurry while close-up tasks like reading or scrolling a phone remain sharp. It occurs when the eye grows too long or the cornea and lens bend light too strongly, causing the image to come into focus in front of the retina rather than directly on it.

Once considered mainly genetic, myopia has surged worldwide in ways heredity alone can’t explain. The biggest culprits? Modern lifestyles: endless hours of near work (especially on screens) combined with limited time outdoors. By 2050, nearly half the world’s population is expected to be myopic, with some regions already seeing rates above 80% among young adults.

The severity of myopia is measured in diopters (D). A simple way to think about it is in terms of the farthest point you can see clearly. At –1 D, that limit is about one meter. Increase the prescription to –3 D, and the clear zone shrinks dramatically to just 33 centimeters. Traditional glasses and contact lenses shift the image back onto the retina, providing clear vision with single vision lenses.

In its simplest form, distance single-vision lenses correct nearsightedness. But in reality, many people face a mix of challenges, such as struggling to see up close as the eyes age (presbyopia) or dealing with blurred or uneven vision resulting from other irregularities in the eye. When these conditions overlap, the corrections become more complex, and the compromises of traditional lenses become even more obvious.

3. Presbyopia: The great equaliser

Starting around the age of 40, the crystalline lens in the eye (the clear, flexible part just behind your iris) begins to stiffen. When you’re young, this lens works a bit like the autofocus in a camera: it changes shape effortlessly so you can shift focus from something far away to something close by in an instant. As the lens loses its flexibility, that quick adjustment slows down, making near vision harder and harder to maintain.

The result is the same for everyone: focusing on nearby objects becomes harder. Fine print starts to blur, menus need to be held farther away, and brighter light is needed for reading. Before long, reading glasses or progressives become a constant companion.

Here’s the catch: the crystalline lens of the eye can only “add plus” when it refocuses.That’s why someone with mild myopia (say –1 diopter) can still see up close through their distance glasses, the eye can pitch in some extra focusing power. But the reverse isn’t true. If you put on +1 glasses and try to look far away, the eye can’t “add minus” to cancel that out. That’s why presbyopia glasses need a relatively small reading area, and why this condition has always been such a challenge for traditional optics.

Traditional lenses currently manage this with static instruments: bifocals, progressives, or opting for different glasses for different tasks. But these solutions bring compromises of their own: distortion that bends straight lines into curves, narrow “sweet spots” that force you to tilt your head just to find focus, and an awkward adaptation period where the world can feel like it’s swimming until your brain catches up.

That’s why certain everyday tasks can feel close to impossible. Reading a recipe while glancing up at the stove, checking your phone while walking down the street, or switching between a laptop screen and a colleague across the table – each requires constant head movements and micro-adjustments. Instead of vision working in the background, you become hyper-aware of it, managing your glasses more than the task itself.

4. The “adaptation period”: Why new glasses don’t work instantly

Putting on a new pair of glasses isn’t always the instant fix people expect. Adjusting to new lenses is about retraining the entire visual system. When the optical system formed by the human eye and the external lens changes, the brain has to learn how to process the world all over again.

The effects can be disorienting: straight lines bending unnaturally, floors seeming to tilt, or a swimming sensation as the world shifts with every glance. Over time, the brain works hard to smooth out these distortions, but the process can be surprisingly demanding.

There are ways to make the process easier, like updating eyeglass prescriptions regularly so the brain isn’t forced to leap across huge changes at once. Still, the fundamental problem remains – static lenses impose compromises the visual system must wrestle with before clarity feels natural again.

5. Digital eye strain: Are our screens quietly destroying our eyes?

We live in front of screens more than ever before: phones, laptops, tablets, endless hours of near work. And while digital devices have reshaped how we live, they’ve also introduced something we’re only beginning to understand, which is digital eye strain.

Eye strain isn’t a well-defined condition but a collection of symptoms: headaches, dryness, blurred vision, burning, and even neck and shoulder pain. Research also links prolonged discomfort to broader impacts on well-being, from fatigue to anxiety. In children, heavy screen use may even interfere with visual development and accelerate the progression of myopia.

The science behind it isn’t as simple as “tired eyes.” Two key systems take the hit:

• Your tear film — the thin, protective layer that keeps eyes moist. Stare at a screen and your blink rate drops from around 15 times a minute to as low as 3 or 4. It’s like forgetting to oil the gears of a machine: friction builds, moisture evaporates, and discomfort sets in.
• Your focusing muscle (the ciliary muscle) — the one that changes the shape of your lens to shift focus. Near work keeps it locked in “close-up mode.” Over time, that constant tension can cause spasms, making it hard to switch back to distance vision. Imagine clenching your fist for an hour and then trying to relax it — the release is slow and stiff.

How can we protect your eyes from the digital strain? Common advice like the 20-20-20 rule (looking at something 20 feet away every 20 minutes for 20 seconds) can help, but its effectiveness is mixed, because sometimes the eyes never fully relax, due to accommodation spasms that keep the eyes locked in “close-up mode”.

Eye drops can provide short-term relief, but they don’t solve the real causes. Taking longer breaks from near work, along with making sure to do full blinks, can be more effective, giving the tear film time to stabilise and the ciliary muscle a chance to reset.

Another important factor in minimising eye strain is optical accuracy. When your near-vision correction has the optimal optical power, the eyes no longer need to overcompensate, which reduces unnecessary strain on the focusing system. A correct optical prescription can make everyday tasks noticeably easier on the eyes, helping prevent strain from building up in the first place.

At IXI, we are creating the future of eyewear with the world’s first autofocus glasses. The technology is hidden inside the frames, tracking your eye movements so the lenses can adapt instantly. Whether you are looking near or far, they deliver the right optical power at the right moment.

Our aim is simple: to bring vision correction closer to the natural adaptability of the human eye, so your eyes can work the way nature intended. If you would like to be among the first to experience it, join the waitlist and follow along as we shape the future of eyewear.