> And yes, 6000 lux is a lot of light. Staring at a 100W incandescent light bulb from 1 meter away will put about 100 lux on your eyes, by way of comparison.
That puts 6000 lux firmly in the "my eyes hurt, this cannot be good" category.
Take a high-powered flashlight - the kind the police use. Hold it at arm's length. Point it straight in to your eyes. That's about 6000 lux.
They had also dilated the rats' pupils with atropine, making the acute exposure test equivalent to, or perhaps worse than staring at the midday sun for 24 hours straight.
Even the lower-level chronic exposure test used 500 lux with light from all directions so there's no way to look away. We don't use light that way in reality, and while I'm sure the intent was to accelerate the test, I can't help but suspect it's the equivalent of testing whether bathing in warm water might be harmful by boiling rats alive.
That puts 6000 lux firmly in the "my eyes hurt, this cannot be good" category.