Ask HN: Would you buy a red-pixel only screen? | Hacker News Reader

Ask HN: Would you buy a red-pixel only screen?

docs.google.com

1 pointmacrolet8 comments

Many phones have OLED screens that are capable of emitting only red light, if a software filter is applied, so there's no need to develop specialized hardware.

Chances are that the reason blue-light filtering glasses and night-time mode aren't working for you is the same reason that it doesn't work for anyone; studies show that the color temperature of light doesn't affect sleep or circadian rhythm:

https://www.bbc.com/future/article/20260407-the-blue-light-f...

https://www.manchester.ac.uk/about/news/researchers-discover...

A red-only filter for your phone would be great for preserving night vision, though.

If you want help sleeping, getting lots of light in the morning is greatly beneficial, especially full-spectrum light, including infrared. It's also helpful to avoid alcohol and caffeine, especially so later in the day.

Me drinking 4 cups of coffee and blaming phone light for my sleep problems.

I agree, OLED can emit red light only. However, I am questioning whether that means there really is no need for red-only displays. As that mode on conventional displays (even on OLED) wastes pixels and is, more importantly, optional.

For the past few weeks, I had trouble falling asleep. Mostly due to late night screen use. Even though I use blue-light filtering glasses and night-time mode on my screen.

Then I thought to myself, why do I need to fight with this? Why cant I just buy a screen that has only red pixels (LEDs) on it?

So, I made a google form to check for interest in such a display. Or just comment here. Would you be interested in buying a display that uses only red pixels (no blue or green light) to reduce eye strain and improve sleep quality, even if it means limited color accuracy?

> (no blue or green light)

Coincidentally, i saw several headlines yesterday (now long gone from my news feed) claiming that blue light filters are not nearly as effective as once believed. It may be worth researching the current status on that info before committing to a red-only screen. (There's no way i'd buy one, in any case.)

The "pixels" of a screen are composed of red, green, and blue sub-pixels. Software filtering mostly reduces the blue and green light emitted, but does not eliminate it. And the sensors in our eyes, the rods, are less sensitive to red color, when compared to blue or green. This means that looking at a red-light only monitor would be closer to "night" vision.

FWIW, iOS already allows color filtering to display only red (or any other color).

I believe macOS does too; and then there's the venerable f.lux, which not only has warmer tinting but also "Darkroom mode" (red only).

That is a valid argument against. A conventional display can simulate a red-only display, while the reverse is not possible.

However, there are two technical points, and one non-technical point, I would like to reply with.

First, as in my other comment, software filtering mostly reduces the blue and green light emitted, but does not eliminate it.

Second, these blue and green pixels become "useless". A monochromatic red-pixel display could have higher resolutions, or lower complexity and power use.

Third, and the biggest reason (in my opinion), is that it is not optional. A red-pixel only display, does not allow you to change "the warmness" or adjust the colors. Instead it forces its own color mode.

Reply on news.ycombinator.com