Yep..all 3 things...
It increases light bulb life (not sure why 'cos I remember getting physics lesson at school explaining how th einitial switching on of a lightbulb places the maximum surge through it)...but these bulbs are designed so that they get switched off before reaching their peak temperature. (I think) All too scientific for me.
Also easier for humans to see.
Hope it doesn't scare the frogs !!
