I think an argument can be made for both sides here. On one hand, like Gabbay said, lash primers can add a lot of weight if you’re not careful and can make your mascara clumpy. On the other hand, though, I have a few lash primers that I absolutely swear by. Using a lash primer has also been one of the only things that prevents my mascara from smearing all over my under-eye area. My under-eyes are is already naturally oily, but now that I use an eye cream as well, let’s just say it doesn’t always mix well with mascara. 

I think that primers work as long as you use the right formula for your lashes and don’t go overboard on using one. A little trick I also use is to let the primer dry just a tad before applying your mascara, otherwise, it can get a bit messy and clumpy. If you wait a minute though, there are usually no issues. For the best of the best ones, keep reading below.