From Glasses to Code - The Personal Journey Behind Harmonia Vision
After almost a decade wearing glasses for myopia and astigmatism, I built an extension that finally understands what my eyes need.
The Day Everything Changed
It was mid-2016 when I first put on glasses. Myopia and astigmatism - two words that would become permanent companions in my life as a developer.
I still remember that first moment of clarity. The world suddenly had edges again. Text on screens was crisp. But I also discovered something frustrating: the default settings in my code editor weren’t designed with my eyes in mind.
The Endless Tweaking
Over the years, I developed a habit. Every time I set up a new machine or switched editors, I’d spend time adjusting font sizes, trying different fonts, playing with line heights. It was a ritual - sometimes taking hours to feel “right.”
But it was always guesswork. How big should the font be? Should I increase line spacing? Why does this font feel blurry even at larger sizes?
I never had clear answers. Just trial and error, over and over.
From Harmonia Theme to Harmonia Vision
When I built Harmonia Theme, my focus was on colors - reducing visual noise, creating a calm palette that wouldn’t strain my eyes during long sessions.
But colors are only half the story.
Typography matters just as much. For someone with astigmatism, letters that are too close together blur into each other. For someone with myopia, small text means constantly leaning toward the screen. And eye fatigue compounds everything.
I realized I needed something more systematic. Something that understood the why behind each adjustment, not just the what.
Understanding My Own Eyes
I started researching how different vision conditions affect screen readability:
- Myopia makes distant objects blurry - on a screen, this translates to needing larger text to maintain a comfortable viewing distance.
- Astigmatism causes light to scatter irregularly, making closely-spaced characters blur together - increased letter spacing helps.
- Eye fatigue benefits from more vertical breathing room between lines.
- Light sensitivity means high-contrast or heavy fonts can feel uncomfortable.
Each condition has its own needs. And when you have multiple conditions (like I do), they interact in complex ways.
Building the Calibrator
Harmonia Vision started as a simple idea: what if my editor could understand my prescription?
I built a calibration engine that considers:
- Which conditions you have - select one or multiple from a list.
- Your actual prescription values - sphere and cylinder, if you want precise recommendations.
- Your current settings - as a baseline that recommendations won’t go below.
The engine uses empirically-derived thresholds based on real comfort profiles.
When I ran the calibrator on my own setup, the results were eye-opening (pun intended). My manual settings after years of tweaking were:
| Setting | My Manual Config |
|---|---|
| Font Size | 18px |
| Line Height | 0 (auto) |
| Letter Spacing | 0 |
| Cursor Width | 1px |
The extension analyzed my conditions and recommended:
| Setting | Recommendation | Why |
|---|---|---|
| Font Size | 19px | Slightly larger for sustained comfort |
| Line Height | 1.6 | Better line tracking with astigmatism |
| Letter Spacing | 0.3px | Reduces character blur from astigmatism |
| Cursor Width | 3px | Easier to track with myopia |
The line height and letter spacing changes were things I’d never thought to adjust - but once I tried them, the difference was noticeable. Lines of code felt less cramped, and my eyes didn’t have to work as hard to distinguish similar characters.
It was validating to see the algorithm suggest improvements I didn’t even know I needed.
The Safe Apply Workflow
One thing I learned from years of tweaking: sometimes you make a change and it looks great… until it doesn’t. Maybe the font is too big for your monitor. Maybe the line height feels wrong after an hour of coding.
So I built in a safety net:
- Automatic snapshots of your settings before any change.
- Live preview to test in real-time.
- One-click revert to go back to your previous comfortable state.
No more digging through settings to remember what values you had before. Just click “Revert” and you’re back.
Privacy by Design
Your prescription is personal medical information. I didn’t want to build something that sent that data anywhere.
Harmonia Vision is completely local:
- No telemetry or analytics.
- Prescription values are used only for calculation, never stored permanently.
- All settings live in your VS Code configuration.
- The code is open source - you can verify every line.
What I Hope You Get From It
If you wear glasses, have eye strain, or just find yourself constantly tweaking editor settings - I built this for you.
It’s not a replacement for proper eye care. Please see your optometrist regularly.
But it can help you find a starting point that actually considers your eyes, not just generic defaults designed for perfect vision.
A Decade Later
Almost ten years with glasses now. My prescription has changed a few times. My monitors have changed. My preferred themes have changed.
But the fundamental challenge remains: making text on screens comfortable for eyes that need a little help.
Harmonia Vision is my answer to that challenge. A small tool that applies what I’ve learned from years of adjusting, researching, and understanding my own vision.
I hope it helps your eyes as much as it helps mine.
Where to Find It
Harmonia Vision is available now on the Visual Studio Code Marketplace.
Thanks for Reading
Building developer tools that focus on accessibility and comfort feels meaningful to me. We spend so many hours looking at code - it should be as comfortable as possible.
If you try Harmonia Vision, I’d love to hear how it works for you. Especially if you have different vision conditions than mine - your feedback helps make it better for everyone.
Take care of your eyes.