Avoiding eye damage

Is there an approximate guide on how lumens + distance has the potential to cause eye damage? I use a PD35 v2 in the park at nights when walking my dog, using turbo I always try to keep the centre spot of the beam away from their eyes. Is it possible to approximately calculate what the safe distance is? I just want to get a ballpark feel for what’s safe and what isn’t.

I would guess that on medium (150 lumens) I can comfortable shine the line towards the dog from 10 feet or so away without risking any damage but I still try to avoid putting the spot into the their eyes. Turbo not so sure, probably needs to be further away but how far? Is there any research on this? My most common use-case for turbo is finding dogs when they’ve run off somewhere, usually that’s 30-40 feet or more.

Maybe I’m over-thinking this but I really don’t want to damage my dog’s eyes and I’m aware that this light is very powerful on the high settings.

Thanks