From Glasses to Code - The Personal Journey Behind Harmonia Vision

Published: (January 18, 2026 at 05:36 PM EST)
3 min read
Source: Dev.to

Source: Dev.to

The Problem

Every time I set up a new machine or switched editors, I spent hours tweaking font sizes, fonts, and line heights to feel “right.” It was always guesswork:

  • How big should the font be?
  • Should I increase line spacing?
  • Why does a font feel blurry even at larger sizes?

Research on Vision Conditions

I dug into how different vision conditions affect screen readability:

ConditionImpact on readabilityTypical adjustment
MyopiaDistant objects appear blurry → need larger text to keep a comfortable viewing distance.Increase font size.
AstigmatismLight scatters irregularly, causing closely‑spaced characters to blur.Increase letter spacing.
Eye fatigueRequires more vertical breathing room.Increase line height.
Light sensitivityHigh‑contrast or heavy fonts can feel uncomfortable.Use softer color palettes and moderate contrast.

When multiple conditions coexist, the interactions become more complex.

Harmonia Vision: A Systematic Solution

Harmonia Vision started with a simple idea: what if my editor could understand my prescription? I built a calibration engine that considers:

  1. Selected conditions – choose one or more from a list.
  2. Prescription values – sphere and cylinder for precise recommendations (optional).
  3. Current settings – used as a baseline so recommendations never go below your existing comfort level.

The engine uses empirically‑derived thresholds based on real comfort profiles.

Calibration Results

Running the calibrator on my own setup produced the following comparison.

My Manual Configuration

SettingValue
Font Size18 px
Line Height0 (auto)
Letter Spacing0
Cursor Width1 px

Engine Recommendation

SettingRecommendationWhy
Font Size19 pxSlightly larger for sustained comfort
Line Height1.6Better line tracking with astigmatism
Letter Spacing0.3 pxReduces character blur from astigmatism
Cursor Width3 pxEasier to track with myopia

The line‑height and letter‑spacing changes were things I’d never thought to adjust, yet they made a noticeable difference: lines of code felt less cramped and my eyes didn’t have to work as hard to distinguish similar characters.

Safety Net Features

  • Automatic snapshots of your settings before any change.
  • Live preview to test adjustments in real time.
  • One‑click revert to return to your previous comfortable state.

Privacy & Local‑Only Operation

Your prescription is personal medical information. Harmonia Vision never sends that data anywhere:

  • No telemetry or analytics.
  • Prescription values are used only for calculation and are never stored permanently.
  • All settings live in your VS Code configuration.
  • The code is open source—you can verify every line.

Availability

Harmonia Vision is available now on the Visual Studio Code Marketplace.

Closing Thoughts

If you wear glasses, experience eye strain, or constantly tweak editor settings, this tool is for you. It’s not a replacement for proper eye care—please see your optometrist regularly—but it can provide a solid starting point that considers your eyes rather than generic defaults designed for perfect vision.

Almost ten years with glasses have taught me that the fundamental challenge remains: making text on screens comfortable for eyes that need a little help. Harmonia Vision is my answer—a small, open‑source tool built from years of adjusting, researching, and understanding my own vision.

If you try Harmonia Vision, I’d love to hear how it works for you, especially if you have different vision conditions. Your feedback helps make it better for everyone.

Take care of your eyes.

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