I had my eyebrows tattooed some years ago, not because they were particularly sparse, just very very pale. It was a friend of my daughter’s, she did it for free as a demonstratoin in her salon. I have to say not painless but I was delighted with the result. I was a little naive in thinking as a tattoo it would last for ever. It didn’t. I had them touched up a few years later, obviously had to pay for that which was quite expensive. I haven’t had it done since. If you do go for it find someone really good, do research.
Charity Shops Making Donations Uncomfortable
and whilst the brow would have been much ignored in my makeup routine once upon a time, it's now the most important part. Never go out without having done my eyebrows these days.

