Why I picked the Iris keyboard for my RSI

In a recent video, I talked about my RSI and keyboard ergonomics. There I showed the split keyboard I have been using, called the “Iris” by keebio (thanks again to “Andreas” for making this possible). The reasoning behind my choice may be of interest to others, so I am documenting it herein.

I am not affiliated with any of the entities I mention and am not providing any related links for this reason.


I wanted a keyboard that consisted of two separate parts, so that I could space them apart to keep my arm and wrist aligned on each hand.

I thought that a columnar stagger (explained in the aforementioned video) would benefit me, as its combination with the split keyboard enforces benign typing patterns like typing b with the left index, not the right one (I use Qwerty, by the way).

The combined profile of the keys—cap and switch—should not be low. I find those harder to use, as I bottom out more easily.

Lastly, I wanted my keyboard to use QMK firmware, because it is a well-established open-source project. Programming the keyboard to do what you want is, in my opinion, the irreducible factor of this endeavour.

Why not buy a more established option like the ZSA Moonlander or Dygma Defy?

The ZSA Moonlander looks promising, though I got the impression that its thumb cluster would not work for me. I was concerned that those bespoke thumb keys would be hard to replace, should I ever want to try a different set of keycaps.

I also found its tenting setup strange with how it bends the thumb cluster (tenting is when we raise the inner side of the keyboard, or of each split in this case, to keep our arms closer to a more natural position—we avoid “pronation”).

As for other reasons not to opt for the Moonlander, its cost would have been much higher than that of the Iris. Plus, I did not like its appearance.

Another highly marketed option, based on my research, is the Dygma Defy. It too has its own unique thumb keys, which may work great though do entail limited compatibility. And it costs a small fortune (perhaps for very good reasons—not judging).

How about the MoErgo Glove80 or the Kinesis Advantage360?

Those keyboards are designed to create a well whose deepest point is somewhere along the home row. Their goal is to make the upper and lower rows easier to reach. I do not know if this is necessarily more ergonomic, because it must also depend on the length of the fingers, no? Due to this uncertainty, I did not want to take any risks.

Other than that, the Glove80 uses low-profile switches, which runs counter to my requirements. While the Advantage360 has a fixed length which has a built-in assumption about how far my hands are spaced out. I did not even check the rest because of these.

Why not build a keyboard for cheap using a kit?

A popular option among enthusiasts is to buy a kit and piece together their new keyboard. This is something I will most probably do in the future, though I did not want to take any chances at such an early stage because of my injury. Any delay in easing my pain would make my condition worse. I can always tinker with keyboard kits in the future.

In theory, the Do-It-Yourself route pushes the nominal price down as you assume the assembly costs, paying opportunity cost for the time spent tinkering. Though this will likely not be true for rookies, as they will need to experiment a bit, breaking—and paying for—stuff in the process, before they eventually get the hang of it.

Put differently, my understanding is that the argument in favour of DIY is not chiefly financial: it rather is about the customisation options it opens up and the feeling of accomplishment it engenders, both of which appeal to me in principle.

Number of keys and their firmware prerequisites

Many enthusiasts try to reduce the number of keys they are using to concentrate everything around the home row. They do this by defining more layers, using home-row modifiers, and combinations that translate into other keys like a simultaneous press of j and k to send Esc. As such, they do not need a number row or even a thumb cluster with modifiers. It is an interesting approach that I might explore in earnest at a later point.

I think going full reductionist without prior experience is a mistake. It is better to have more keys for experimentation and to take things slowly. The split and the columnar layout are already a huge change: adding too many of those all at once will feel overwhelming.

Having more keys gives you flexibility. You can retain your muscle memory and operate within your comfort zone. Once you are prepared to reduce the number of effective keys, you simply set up QMK to disable the extra keys on your board. If that works for you, then you know what you are buying next, while blithely working with your new layout. Otherwise you revert back to a known working setup.

That aside, the ultra-minimalist design relies on a well thought out implementation of the relevant firmware features. Without home-row modifiers and/or key combinations, it will be hard to use, if not outright unusable.

As someone who writes A LOT, I am not a fan of the home-row modifiers arrangement (where keys on the home row act as modifiers when held, but otherwise send their usual code when tapped): it is error prone as I keep misfiring no matter the tweaks I make to the firmware. Compounding the problem is the fact that I use Emacs for all my typing, so I might accidentally trigger some command that deletes too much text, which is annoying.

For the number row, I do not share the concern of this being troublesome to reach, given the columnar stagger. Though, yes, those keys are harder to type correctly with a row stagger.

As for key combinations, I suspect they will have the same issues as the home-row modifiers and I will keep mistriggering them. Well, unless we are talking about some keys that are too far apart from each other, in which case the combo will be more accurate but less convenient to access.

My concern is with complexity. While we can add a zillion layers and combinations with highly sophisticated interactions, I find it simpler to just stretch my finger a tiny bit. Come on! Thumb clusters are also easy to work with, but more on that below.

The thumb cluster of the Iris and one-shot modifiers

If you look at the Iris, you will notice that the thumb clusters have a shape like this on the left split:


And its flipped version on the right…

The uppermost key, which I label as 4, may be hard to press. I personally do not have an issue here because:

  • I use taller caps for the keys at either end of the cluster (1 and 4). This makes it easier to use my thumb without twisting it.

  • I have set up one-shot modifiers, meaning that I do not have to press and hold those keys to do what I want.

One-shot keys are a QMK feature that allows us to register a “hold” action for the next key. Instead of holding down Shift and then typing a letter, we tap Shift and then the letter. The interval between the two key presses is configurable: after that the one-shot key expires (ESC produces the same effect on demand).

What is also configurable with QMK are one-shot keys that become “sticky”. This means that they pass their action to all following key presses until we manually abort them. Think about typing the word “QMK” by holding down Shift: you must press and hold the modifier and then type the three letters. With sticky modifiers, you activate the modifier, type Q, M, K, and then deactivate the modifier.

This “shift lock”, “control lock”, etc. is easy to access via a multi-tap of the one-shot key. What counts as “multi” is configurable: I set it to a double tap. Thus, I double tap Shift and then input the longer sequence of shifted key codes: no pressure for the thumb.

These work in combinations as well, such as if we want to input M-^ in Emacs a few times, where we lock both Shift and Alt and then type 6. Tap those modifiers once to cancel their stickiness.

For the technicalities, check my QMK files: https://github.com/protesilaos/qmk/tree/master/keyboards/keebio/iris/keymaps/prot.

The simple tenting setup of the Iris

What I am using right now is a middle layer that has holes where we can insert regular nuts and bolts. We place them in it and—voilá!— there is the tenting angle we desire. It is simple and effective. I have been typing this way for weeks and feel much better than before.

What about a nice case?

Keebio is selling an aluminium case for the Iris, though (i) it is expensive and (ii) it is not a requirement of mine. I guess the casing will change the keyboard’s acoustics, ceteris paribus, and will add an extra “wow” factor to its looks. These are marginal changes, which do not justify the price. The current sound profile is fine to me as-is, while I am not going anywhere with the keyboard to be concerned about its appearance: it looks good to me, which is all that matters.

Is this the “end game”?

I think so, yes, even though I know this is a bold claim for a newcomer. I did extensive research before making my decision. I knew what my needs were, had a clear goal in mind, and decided accordingly without hesitation. This is how I operate and do not renege on my decisions.

The few tweaks I still want to make pertain to inconsequential experiments with QMK (to refine RGB lighting feedback, mostly for fun). I do not want to implement any other changes to the keyboard itself, nor to further experiment with alternative switches or keycaps. The Iris works for me and I treat it as a tool that empowers me to do what I actually care about: to write at length.

If I ever choose to play around with keyboards, such as to build one by using a kit, that will be for the recreational value of it, not out of a pressing need for reform.