July 2023


Solve Myopia in a Pinch with an iPhone

The discussion of how Apple’s Vision Pro puts a little screen in front of each eye reminded me of a neat discovery I made a while ago: if you’re near-sighted, you can use an iPhone to stand in for your glasses and even see in the dark.

Until several years ago, I wore contacts to correct my myopia, switching to glasses every night at bedtime. One night, after I had taken my contacts out, I realized my glasses were somewhere downstairs because I’d been traveling and hadn’t yet fully unpacked. Although I can see well enough to navigate the house—I’m fine with large shapes and colors—I would have had difficulty finding glasses on a table or counter, especially in a dimly lit room. Between the clear lenses and thin metal frames, there’s just not much to see.

That was when I had my brainstorm. I see perfectly at about a hand’s length from my face. Though problematic for everyday life, that’s helpful for close-up work on electronics or other small objects, and I also often read in bed without glasses using my iPhone, which is easy to hold at that distance.

My contacts were off, I needed to go downstairs to find my glasses, and my iPhone was at hand. I opened the Camera app and held the iPhone in front of my face so the viewfinder was in focus. Looking around with the iPhone blocking my eyes felt odd, but it worked like a charm. To avoid having to turn all the lights on and off (this was before I had wired them all up with HomeKit-compatible switches), I switched to Video mode, swiped up on the image to display the controls, tapped the Flash button, and locked the setting to Flash On.

With my ad hoc night-vision goggles in play, I walked downstairs and wandered around the darkened house until I found my glasses. For giggles, I even zoomed the view a few times to see something better than I would have been able to otherwise. I felt like a cyborg.

Demoing the iPhone vision enhancement approach

This screenshot shows what I see on the iPhone screen, which is myself in a mirror so you can see how I have to hold the iPhone.

I haven’t needed to use the iPhone like this again. In 2020, I got tired of having to switch between multiple pairs of glasses over my contacts for reading, driving, and bright sunlight, so I got a single pair of photochromic progressive glasses that work for everything and are with me at all times. But I’ve always remembered just how well the iPhone hack worked and thought that if I was ever in a situation where my glasses were broken, it might be a lifesaver.

In some ways, the Vision Pro is the ultimate version of this hack, combining as it does forward-facing cameras and screens right in front of your eyes. Although Apple has optional Zeiss lenses for those who wear glasses, it’s unclear if they’d be necessary for those of us whose eyes focus at the distance of those screens. We’ll know eventually.

The idea isn’t new, I discovered. The 2015 research paper “ForeSee: A Customizable Head-Mounted Vision Enhancement System for People with Low Vision” by Yuhang Zhao (Tsinghua University), Sarit Szpiro (Harvard Medical School), and Shiri Azenkot (Cornell Tech) proposes a head-mounted vision enhancement system that looks like it’s based on an Oculus Rift headset. It doesn’t seem to have gone any further, though.



The closest I could find to a head-mounted iPhone holder is the obsolete Google Cardboard, released in 2014. It provided a cardboard viewer into which you could slot an iPhone or Android smartphone for VR on the cheap. I even have one, but it lacks a head strap and has built-in lenses for 3D images. Google Cardboard was succeeded by Google Daydream, which does have a head strap but seems similarly obsolete. But both were focused on VR rather than vision enhancement.

Demoing Google Cardboard

However, since Google published instructions and templates for making your own Google Cardboard and many other sites released their own versions, it should be possible to create an iPhone-based vision enhancement system, complete with a head strap. I leave that as an exercise to the reader and will award bonus points to anyone who does it and posts a picture. I’m particularly taken with the person who repurposed his iPhone’s box.




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