Which lighting attributes matter most for lighting my home when prioritizing wakefulness, mood, and easiness on the eyes?

So my partner and I hate yellow lights–honestly, even at night. He switched out most our bulbs with 5000k ones recently which feels a lot better. Obviously this can be a lot though when we DO need things a bit dimmer. However, since learning a bit more about various light qualities (but still don’t know much) I’m wondering how important things like CRI are for just basic home environment.
I’m also curious if there’s well accepted research about lighting your house for being more awake (everything I look up just gives me info for sleep lighting instead…) and what aspect of light affects mood–if that’s something that can be replicated with artificial lights. I’ve got ADHD and struggle with waking up and being sleepy during the day–if I forget to open my blinds before bed to get light in the morning, or if it’s cloudy and rainy, I’ll sleep forever and be groggy all day even if I do get up. The difference in mood and energy just stepping outside on a sunny day can be pretty huge, but there’s unfortunately not much way to let the natural light into my house.
My partner and I also both have some vision issues and the yellow lighting always seems harder to focus under, sometimes leading to migraines for him. But we probably do need a gentler alternative for night-lighting. I don’t know whether we need to use different light sources with warmer lighting, or if dimming our preferred lighting temperature is fine for not keeping us awake.
So yeah–how important is the overall brightness, versus the color temperature, versus the CRI or any other aspects for these things? And is the answer something scientifically backed, or more just people’s preferences?

First of all, I think you’ll find that 95% of people are gonna disagree - vehemently - on the fact that 5000k looks good or “feels better”. I’m firmly in the camp of “that looks absolutely hideous”, but I have had one person here or there specifically ask for it. I say this because you’re starting off at a disadvantage - it’s gonna be really hard to make 5000k work and feel pleasant.

That said, there is some truth to using cooler color temperatures during the day and warmer in the evenings. This is what light from the sun does and it feels the most natural. For this reason, warm-dimming lights are becoming quite popular. These lights will shift their color temperatures warmer as they dim. Lights that are branded as “human centric” will often dim from 4000k down to around 2200k ish (the Elco Koto HC is a great example of this.)

As for CRI - always go for 90+ - that will help eliminate the ugly green/tints in lights and generally just ensures a more consistent light overall. If the light advertises it - try to get a decent R9 value as well (50+). Frankly though that vast majority of people aren’t going to be able to tell the difference between a 90 or 95 CRI bulb.

@Yan
Yeah, I was surprised he said they were 5000k since most things I’ve seen have people saying they prefer much warmer–which is also why I’m wondering if maybe other aspects of the lighting have more to do with why we like/dislike some. But I really don’t like a noticeable yellow tinge, and the color of these bulbs doesn’t seem harsh to me unless I’m already light sensitive or trying to sleep or something. For ease of higher focus visual needs–like reading or writing or working with things up close–is it better to have dimmer cooler lights, or brighter warmer lights?

@Phoenix
Some of your questions are a bit subjective. Although I think most would agree that for the most pleasant of experience, you want to minimize glare. Glare happens when you can see the source of light. To remove the effects, hide the source of light. Light that is bounced on the ceiling can give a soft even shadowless light that fills the room.
Tunable white lighting systems allow you to match the color temperature of the lights to suit the time of day.
The science behind human-centric lighting in a nutshell is to tap into your circadian rhythm. A blue sky with light high above your head (5600k) in the morning and daytime will help you wake up and remain alert. After dinner or getting ready for bed, lighting would be warm and cozy (3200k) (think of a caveman with a fire in his cave; the light is warm and low to the ground, which creates a feeling of safety).
Good lighting design is one thing, but having good control of the lights is something that is often overlooked or overcooked.
Saying you like lighting to have a type of color temp really matters on where, when, and how.

@Yan
I would love to get some of those 4000k warm dim bulbs, but haven’t found anything with an E26 style.

If you are talking about migraines, ADHD, and fatigue, you should consider the effects of flicker. Look at IEEE 1789; it is a good discussion of photobiological effects of flicker and will have recommendations. Try to find lights with modulation frequencies above 3kHz; or conversely lights that are dimmed via constant current reduction (CCR). The problem is nobody publishes this data, or worse yet will advertise “zero flicker” or “flicker free” which is not likely to be true.

@Vesper
Excellent. May help at my house.

You could look into color tuning modules, so you could have up to 6500k during the day and change that all the way down to 2700k at night. Your sleep issues and migraines could be caused by the 5000k; you are getting a TON of blue hazard light all day and all night, preventing your body from producing melatonin and having a proper day-night sleep cycle. Warm light sources have much less blue daytime signal. If you want to dive deep into circadian lighting, check out BIOS lighting on YouTube, specifically the video on CCT tunable; it’s the best of the best, designed for the NASA space station. But you don’t need to go that far, just understanding why the sources and color, but more so spectrum, of the LED is critically important to your correct day-night cycles and what it does to your body. Another option is something like the Xicato Vibrant series, even though it’s 3000k, it’s shifted off the black body curve to mix in more pinks to make whites whiter. So even though the whole environment is still warm and on the 3000k vector, the whites are whiter as it has additional pink to it, removing the yellow appearance on whites. Lots of options, it all comes down to budget and what is most important to you.

@Gale
As others have mentioned, glare and flicker are also critically important to creating an all-round comfortable solution.

Hey OP, I just found your post and was wondering have you come to any conclusions yet? I have a similar dilemma at the moment (ADHDer with bad eyesight and no idea which lighting is best for me).

Vale said:
Hey OP, I just found your post and was wondering have you come to any conclusions yet? I have a similar dilemma at the moment (ADHDer with bad eyesight and no idea which lighting is best for me).

No final life-changing conclusions–still need to look into some of the things people mentioned here like glare and flicker. So far I’ve gotten a few new bulbs. For some reason, I can rarely find color temperatures other than 2700k (warmest and yellowest, what most of my lights were–I hate it) or 5000k (which people are saying isn’t good at night and most people don’t find comfortable, but I prefer over the previous).

So in my kitchen, I got 5000k/daylight high-definition bulbs that have CRI >90. I can’t speak to the overall effect of it on my wellbeing/fatigue, but it’s definitely easier for me to see, and that’s a common workspace for me. I don’t get good natural lighting there usually. The bulbs I changed from were apparently the same brand and type, also HD, similar lumens, just 2700k. So with just the temperature difference change, I prefer it, but probably not great as far as being conducive to sleep if I’m there at night?

However, I also got a 6-pack of bulbs from Costco that were like 10 dollars, CRI in the 90s, and have a switch that lets you change the color temperature! 2700k, 3000k, 4000k, 5000k, and 6500k. I put those in my bedroom ceiling fan. I still think they all look yellow until 5000k, but have kept it mostly on 4000k and sometimes 3000 if it’s on at night. It’s useful at least to be able to compare. In the bedroom, I’d like to have a light on a timer to come on in the morning to help wake me up–I want it to be a wakeful one but also not killer to come on suddenly. Probably if I was going to invest in something fancy that could dim or fade in and be preset and change temperature, the bedroom would be the place.
I’m thinking what people said here about glare might be a problem because all of my lights are direct and unfiltered and on the ceiling. Whenever I’m just chilling, I’m usually laying or lounging, so facing the ceiling.

That’s all I got so far–if I try something that makes a crazy difference, I’ll update.