I’ve just spent several months researching this topic, and doing lots of informal experiments on myself and other people. In other words, I have tried it for myself. :-) If you’re somewhere in the SF Bay Area and want to discuss in more detail, I’d be happy to give a mini-lecture about the subject, or about human color vision more generally.

At the typical brightness of streetlamps outdoors in most cities, humans are using photopic rather than scotopic vision (that is, using the “medium” and “long” cone photoreceptors), which is fairly sensitive to anything between about 500–650 nm. For photopic vision, the bright blue spike of a white LED provides almost no useful contribution to brightness perception.

Under starlight or moonlight and no artificial lights, you would be correct, but that’s not the condition we’re discussing. If outdoor lamps cast no more total light in aggregate than the moon, then bluer wavelengths would be fine. In practice they are several orders of magnitude brighter than the moon, which means they saturate the rods and mostly wipe out scotopic vision.

The cause of the nearsightedness epidemic (e.g. in East Asia) is children not going outside in the sun during the day. The details of the lamps they use at night (indoors or outdoors) are irrelevant to that.

I became interested in this topic because the streetlamps on my street were replaced by white LEDs at ~4000K CCT, and they are truly awful. They cause extreme amounts of peripheral-vision glare, and they make the previously charming street feel like a prison yard or sad industrial warehouse. The previous high-pressure sodium lamps are so so soooo much better.