On a side note, it might not be a good idea to directly glare at powerful LEDs. French Agency for Food, Environmental and Occupational Health & Safety noted [1

On a side note, it might not be a good idea to directly glare at powerful LEDs. French Agency for Food, Environmental and Occupational Health & Safety noted [1] some points that might not be photo-biologicaly safe, the main points being: > spectral imbalance (significant proportion of blue light in white LEDs); > high levels of radiance (high brightness density per surface unit emitted by these very small sources) In the french version of their report, they refer to luminance [2] rather than radiance. The spectral imbalance photochemical risk seems linked with cumulative dose of blue light, so there is also a risk with low but long exposure light LED screens. It also perturbs circadian cycle (flux or redshift might help in that case). See also a previous HN discussion about a warning from the American Medical Association about the spectral imbalance in LED streetlights [3]. -- [1] https://www.anses.fr/en/content/led-%E2%80%93-light-emitting-diodes https://www.anses.fr/en/content/led-%E2%80%93-light-emitting... [2] https://en.wikipedia.org/wiki/Luminance#Health_effects https://en.wikipedia.org/wiki/Luminance#Health_effects [3] https://news.ycombinator.com/item?id=11992946 https://news.ycombinator.com/item?id=11992946