[SamiraShuruk]

One of my students gets lash extensions. They look fabulous but do not work if you have to use eye-makeup remover on a regular basis.

At to the problem above- I think bellydancingcaroline said all the possibilities.
The ones with the feathers may indeed be heavier than regular ones.
Also, before applying you want to 1)trim them down to fit your eyelid and 2) flex and bend it- hold the two ends of the lash band in fingers of each hand, then kind of move your hands like you're playing with an itty bitty mini slinky. You're flexing the lash band in the direction that is is shaped- you're just creating more flexibility to it will work better with your eyelid shape.

I use MAC lashes and Duo glue.