I recently came across a US Government funded study [1] that used anecdata of 12 people–just 12 tired souls!– to put forth a seal on the claim that e-ink screens are better for the human eyes than emissive type of displays.

Edit: Reality however: the opposite is true. Only in some scenarios (like reading under open sun) does one type of screen outdo the other. In most usual cases, that is indoor reading, the emissive display is better for the eyes.

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5929099/