whystrainwhy
I’m in a very similar situation.
I’m using an old Mac, and my Firefox is also stuck on an old version. I can’t update it anymore because Mozilla dropped support for this OS.
The important point is: Firefox old version is actually comfortable for my eyes, even after long sessions.
Like you, I’ve been worried about what I’ll do once this setup becomes completely unusable. I tried using a more “modern” browser that still supports old macOS, namely Pale Moon.
Unfortunately, Pale Moon causes me eye pain and neurological symptoms, even though:
• it’s running on the same Mac
• the same macOS version
• the same screen
So the problem is clearly not the OS or the display, but the browser’s internal rendering pipeline.
From what I understand (according to chatGPT), the difference is this:
• Old Firefox uses a very simple, mostly CPU-based 8-bit rendering pipeline, no constant compositor, minimal color management, and very stable font rendering. When nothing changes on the page, the image is truly static.
• Pale Moon, despite looking like an “old Firefox”, actually uses a much more modern rendering engine internally (modern compositing, higher-precision color calculations, offscreen buffers, continuous redraw at ~60 Hz, more aggressive subpixel font rendering).
Even on an old OS and old GPU, this modern pipeline seems to introduce temporal instability (micro-fluctuations, likely dithering during downsampling, constant redraw), which my nervous system reacts to immediately.
That’s why:
• Firefox 48 = no pain
• Pale Moon (same machine) = pain
So for me, the real issue is not just “browser support ending”, but that newer browsers fundamentally change how the image is generated, even if they still run on old systems.
At the moment, I’m stuck like you: my comfortable browser is frozen in time, and newer alternatives are visually intolerable.