I discovered this after I wasted 30 dollars on a heated eyelash curler that didn't even work.
I heat my regular (metal) eyelash curler with my blowdryer for about 10 seconds on high. I then test it for temperature before I curl each lash. My lashes stay curled all day long!
This page contains the following solutions.
If you curl your lashes with an eyelash curler, try heating the curler in hot water or with a warm blow dryer before curling, it will work like a curling iron for your lashes. By Anna