Laugh lines are caused by repetition of facial movements from laughing, frowning, and smiling.
That's a reason they're called smile lines because you get them from mostly smiling often.
Other causes are too much sun exposure and even just plain ole aging and they can even be genetic.
You can prevent smile lines by applying sunscreen everyday to the affected area where the smile lines appear.
The best and most effective way of getting rid of smile lines is by using Silicone smile patches to get rid of the smile lines.