I've written about this before, but it bears repeating. However good your vision is when you're young, it will change as you get older.

Most people become more farsighted as they age. Typically it starts when you are around 40 and changes rapidly for the next decade. After that it tends to settle down.

More importantly, the lenses in your eyes become more rigid, losing their ability to focus at different distances.

When I was younger, one eye was a bit nearsighted and the other a bit farsighted. This allowed me to get away without glasses longer than I should have. Even if I wasn't seeing clearly with both eyes, I could see at most distances with one eye.

As my eyes' focus distance lengthened, my nearsighted eye attained close to normal vision, and my farsighted eye was focused past infinity. Not good.

When I got my first pair of prescription single vision computer glasses, it was life-changing. Now I could see my laptop screen perfectly. I told my optometrist I wanted something like single vision reading glasses, but adjusted for the distance to my laptop screen, about 20", unlike the typical 16" focus distance of a reading prescription.

In fact, this started to make me fussy about using high-DPI displays (~200 DPI) instead of the low-DPI displays (~100 DPI) I'd previously used. On a low-DPI display I could see the pixels!

It does mean that when I use external monitors with the laptop, I need to have them also at this 20" distance. So to augment the laptop screen, I have a 24" 4K monitor in landscape mode immediately above it, and a second 24" 4K monitor in portrait mode to the left.

Both of the external monitors are at about the same 20" distance from my eyes, and each of the three displays is angled differently so the center of the monitor is aligned with my vision: the laptop display at a typical laptop angle, the one above it closer to vertical (but still tilted a bit), and the one on the left at an in-between angle. The bottom of this monitor is about a half inch above my desk, just enough room to let cables run under it.

This is a fairly glorious setup. All three displays are in focus for me, and the portrait display is great for reading documentation, especially PDF files that are so awkward on a landscape display.

The key to this is the single vision glasses. I have seen so many people try to use progressive lenses with their computers, and they are always craning their neck back so they can see through the lower part of the lens that has a closer focus distance. Single vision lenses let everything be in focus at once, especially with the portrait mode monitor.

Another key is that the computer glasses should have a fairly tall profile, not the truncated rectangular lenses that are so popular. This greatly improves the field of view.

On my last visit to the optometrist they suggested lenses with a blue light filter. I said no thanks on that. Sometimes I do photo editing, and the blue light filter shifts everything to a warmer color. The way I solve the problem of too much blue light is that I simply don't turn my monitor brightness up so high. It is set so a white background is about the same brightness as a piece of white paper in the same lighting.

I also have progressive glasses that I use for everything else when I'm not at the computer. These have magnetic clip-on sunglasses, which are pretty great. Indoors I can leave the sunglasses off and just use the progressives on their own. Because I wear aloha shirts with a pocket, I can keep the sunglass lenses in my pocket and I hardly know they are there. When I step outside or go driving, I just snap on the magnetic clip-ons and I'm good to go.

The frames with magnetic clip-ons are a bit uncommon these days, but they are well worth finding.

If anyone is curious I can look up the brand and exact model number for both the round single vision and the progressives I'm using.