[balfirevic]

Yes, the study [0] used iPads (on maximum brightness).

Some releveant quotes:

"The randomized, crossover protocol design consisted of two conditions: (i) reading an LE-eBook (iPad; Apple Inc., Cupertino, CA) in otherwise very dim room light for ∼4 h before bedtime for five consecutive evenings, and (ii) reading printed books in the same very dim room light for ∼4 h before bedtime for five consecutive evenings."

"Third, in the present study, the LE-eBook was set to maximum brightness throughout the 4-h reading session, whereas, by comparison, the print-book condition consisted of reflected exposure to very dim light."

"Lastly, although the short-wavelength light from the LEeBook may have been responsible for the effects reported here, this study did not include a light-emitting device with longer wavelength for comparison, so our findings may be due to the difference in irradiance level rather than spectral composition."

[0] - https://www.pnas.org/doi/pdf/10.1073/pnas.1418490112

[steve1977]

My eyes would bleed after looking at an iPad with maximum brightness for 4 hours.