It is not unusual for one or two lashes to come out while removing eye makeup. The wiping and pulling motion can cause delicate lashes to fall out; try a cream remover and wash it away with water instead of taking a cotton ball or pad to wipe your lashes clean.
If you have lost some of your lashes, take heart in the fact that they can grow back every 4-8 weeks. And remember, your lashes naturally shed and re-grow so it could just be that you’ve become aware of this process, not that you’re necessarily losing more than normal.
If you are in fact experiencing a more than usual eyelash loss, examine some of your eye habits – do you rub your eyes, pull at your eyelashes, sleep with mascara on, etc. If you are significantly losing your lashes, see a doctor, it could be caused by an infection or an allergy.