I have mine redone/infilled every two weeks but I think it's pointless really as within 5 or 6 days they all fall out anyway.
I started having them done so that I didn't have to wear eye make up and because my lashes are very short and fine, but they only look good for a couple of days.
The lady who does my lashes says that it's normal for them all to fall out after a few days for some clients but I know others that get them done seem to have lashes that last for weeks.
Feeling really fed up as I'm paying £40 a time!