Quote:
Originally Posted by arjaybe
They measured that it took on average ten minutes longer to fall asleep, and that the melatonin cycle was disrupted, and so on. I don't need to list them because we've all read about it. Quibbles about "discomfort level" and brightness and so on can be dealt with in future studies.
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A factor of 33 to 70 times brighter by 6 different illuminance measures is not a quibble.
The light levels should have been approximately matched, either by brightening the background or dimming the tablets.
Quote:
Significance
The use of light-emitting electronic devices for reading, com-
munication, and entertainment has greatly increased recently.
We found that the use of these devices before bedtime pro-
longs the time it takes to fall asleep, delays the circadian clock,
suppresses levels of the sleep-promoting hormone melatonin,
reduces the amount and delays the timing of REM sleep, and
reduces alertness the following morning. Use of light-emitting
devices immediately before bedtime also increases alertness
at that time, which may lead users to delay bedtime at home.
Overall, we found that the use of portable light-emitting
devices immediately before bedtime has biological effects that
may perpetuate sleep deficiency and disrupt circadian rhythms,
both of which can have adverse impacts on performance, health,
and safety.
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They did not find anything they claimed to find. The best they can claim is that use of light emitting readers berfore bedtime [B}might[/B] result in the above. There is a big difference between
does and
might. A factor of well over 30 increase in brightness hopelessly muddles drawing even a tentative conclusion. They could have matched the photopic lux and still have over 39% brighter melanopic lux. Which still leaves the possibility of recommending that the application or system have a "night mode" setting rather than recommending no reading with light emitting readers.