How often do you change hair scissors?

[InsertCleverNameHere]

How can you tell when it's time to buy a new pair of hair scissors? I've had mine for about 5 years.

 

[SherryLove]

i have had mine for seven (7) years; but they are still very sharp and give me nice, clean trims....I guess i will get another pair when the blade gets dull.......

 

[Carefree]

I have a pair by Conair and I noticed with my last trim that they wre pretty dull and I've only had them for about a year. I guess I should invest in a professional pair.