Wow… that is quite a few parameters to consider:
With children I guess you can't really control the Distance, Exposure time or how dilated the pupils might be. What you can control is how powerful and concentrated the light is. So the idea that a few posts here already suggest, to use a low power light with a diffuser on, seems the safest way to go. I think document tape should provide some diffusion. It might be a good idea to get it on the light as seamlessly as possible and without the children watching.
But I also believe that there is no substitute for knowledge. I will definitely make sure my kids (if or when I have a few) know they should not look straight in to any kind of bright light and be careful of where they aim flashlights. Until I can tell they understand and respect the power of modern flashlights, I'd stick with giving them low power lights with diffusers on.
- Output "strength" from the light source.
- Size of the light source (LED die and reflector).
- Distance from the light source to the eyes.
- How dilated your pupils are, i.e. ambient lighting when the light is pointed at the eyes
- Exposure time.
- Which spectrum the light is in might have an affect as well.
- Output: 50 lumen
- Size: Reflector – 16 mm / LED < 2 mm (pretty small)
- Distance: 25-30 centimeters
- Pupils: Not more than halfway dilated.
- Exposure time: Less than a second
- Spectrum: Not a clue. But I'm sure someone can tell me.
With children I guess you can't really control the Distance, Exposure time or how dilated the pupils might be. What you can control is how powerful and concentrated the light is. So the idea that a few posts here already suggest, to use a low power light with a diffuser on, seems the safest way to go. I think document tape should provide some diffusion. It might be a good idea to get it on the light as seamlessly as possible and without the children watching.
But I also believe that there is no substitute for knowledge. I will definitely make sure my kids (if or when I have a few) know they should not look straight in to any kind of bright light and be careful of where they aim flashlights. Until I can tell they understand and respect the power of modern flashlights, I'd stick with giving them low power lights with diffusers on.