Why????? Twice! OVERNIGHT EVERY SINGLE UPPER AND LOWER lash broken off!!!

13 weeks ago i went to bed OVERNIGHT EVERY SINGLE UPPER AND LOWER lash broken off!!! Down to a stubble.
They grew back and then about 13 weeks later again I wake up with all upper and lower lashes completely broken off with a tiny stubble. The dermatologist and eye doctors (which I went to both times) have no idea why.
Other than mites or mascara, why could this happen? No problems with hair anywhere else.