Patrick Burrell
Most of the time, I see the world in two.
I have intermittent exotropia: one of my eyes drifts outward, breaking my brain’s attempt to fuse the two images it receives into one. When it happens, the world doubles: two of everything, layered slightly apart. My brain knows this isn’t right, so it suppresses one image, which is exhausting in its own way.
I also live with an epiretinal membrane: a thin layer of scar tissue across my retina that distorts what I see, as if someone laid a piece of rumpled cellophane over my central vision. Add myopia, astigmatism, and the diplopia that comes with all of the above, and you have a visual experience that’s genuinely complicated.
Conventional optometry has done what it can. My current glasses include prismatic correction to address the double vision, but it’s a compromise, not a solution. I own two pairs: one optimized for distance and driving, another for close work at a laptop. For anything closer still (reading a phone, for instance), I take my glasses off entirely. Three different focal situations, three different answers, none of them complete.
Surgery has a poor track record for exotropia in adults. The epiretinal membrane sits right at the center of my vision, beyond most conventional reach.
I’ve made peace with it, mostly. But I don’t think this is as good as it gets.
Last year, I scheduled a Vision Pro demo at the Apple Store. I wanted to see what the fuss was about.
The dinosaur was spectacular: that moment it looms over you and you feel the instinct to step back, you understand why it’s in there.
But what stayed with me wasn’t the dinosaur. Somewhere in that half hour, I started doing a different kind of inventory: eye tracking, per-eye displays, real-time spatial rendering. I wasn’t thinking about entertainment anymore. I was thinking about my eyes. About everything this device was already measuring and computing that happens to be exactly what you’d need to address the kind of vision problems I have. That thought kept coming back for weeks.
A different kind of lens
My son Derek holds a doctorate in photonics. His graduate work was on imaging through random media, developing techniques to recover clear images through turbulent, scattering environments that would normally destroy them. He now works in free-space optical communication, transmitting data precisely through open air at scale.
His research partner has taken a different direction: holographic vision correction. The idea is to use holographic optical elements (engineered interference patterns that sculpt light into almost any shape) to correct visual aberrations that conventional optics simply can’t touch.
These aren’t theoretical problems. They’re being worked on right now, by people who understand exactly what’s at stake.
What Apple Vision Pro makes possible
Apple Vision Pro is a remarkable device for many reasons. But from where I sit, and from where Derek and his partner sit, it’s remarkable for a specific set of capabilities that don’t appear in any product review.
Taken together, these capabilities describe a platform that could, in principle:
- Compensate for exotropia in real time.
- When eye tracking detects a drift event, the per-eye displays could apply a vergence correction, shifting the rendered image to meet the drifted eye where it actually is, maintaining binocular fusion rather than forcing the brain to suppress one image.
- Apply inverse metamorphopsia correction for the epiretinal membrane.
- The distortion pattern caused by an epiretinal membrane is characterizable: it causes a condition called metamorphopsia (the perception of straight lines as wavy or distorted), and it’s precisely the kind of aberration that techniques from imaging-through-random-media research are designed to reverse. A personalized inverse distortion map, applied to the display, could counteract the membrane’s effect on visual perception.
- Deliver wavefront correction unreachable by conventional lenses.
- Combined with holographic optical elements as part of the display path, Vision Pro could provide correction profiles that are simply not achievable with ground glass: personalized, dynamic, and continuously adapting.
Why now
When Apple Watch launched in 2015, its purpose wasn’t immediately obvious: a fashion accessory, a notification device, a watch. A heart rate monitor too, but still a watch. It took an ECG sensor, then fall detection, then sleep analysis and hypertension monitoring for Apple Watch to become what it now is: one of the most consequential health monitoring devices in the world. The hardware preceded the killer use case, and the use case arrived on its own schedule.
I think about Apple Vision Pro in that context.
The convergence of photonics expertise, holographic optical engineering, and Apple Vision Pro’s hardware creates a window. The technology to characterize these visual conditions precisely exists. The optical theory for correcting them exists. What hasn’t been done is building the closed loop: measure the aberration, model the correction, deliver it through a display system sophisticated enough to actually implement it.
Apple Vision Pro may be the first consumer device sophisticated enough to close that loop.
Who I am
I’ve been a software engineer since 1988. I have a BS in Electrical Engineering from the University of Michigan. I’ve spent my career thinking carefully about systems, feedback loops, and the discipline of describing what I actually observe versus what I expect to observe, which turns out to be useful training for being a research subject with a complex visual condition.
I came to Apple late, through the side door. I was a committed Windows user for years. Then in 2006, I bought an iPod, and something clicked. Not just the device, but the philosophy behind it: that a hard problem, solved with enough care, produces an experience that feels inevitable in retrospect. I’ve been in the Apple ecosystem ever since. I mention this because it’s relevant: I understand why Apple, specifically, is the right place to have this conversation. Not because of loyalty, but because I’ve watched you solve problems that way before.
I’m patient. I’m precise about what I experience visually, not given to embellishment or minimization. I can describe what I see, what I don’t, how it changes, and under what conditions. The engineering background means I can participate meaningfully in designing and iterating on a correction approach, not just passively receiving one. I have a well-developed sense of humor and a deep well of optimism, both of which I’ve found useful when the world is in two.