aperatures

For those who live in colder climates, do you often experience fogging up of the scope or red dot lenses? If so, what temperatures and humidity levels would you say I should beware of this occuring? I’m aware that there are preemptive methods to avoid this, however if a scope can’t be trusted...

I have read that someone at aged 60 would need three times the amount of light during the night to see as clearly as someone at aged 20. For those of you with older eyes, would you say that a scope is worth the purchase for shooting at 300 yards during dawn or dusk? The reason I ask, if anyone...