if you use synthetic salon nails or thimbles, this is of no interest to you.
I just had a "oh duh" moment. In the past when I had a tear showing up on the nail I tried to repair it with "hard as nails" or some other product one would find in the nail polish section. Those products never worked for me - not once.
I just ripped my nail the other day. Not all the way off, just a tear. It finally occurred to me to use super glue. Now THAT works! Apply carefully using a tooth pick. Just over the tear. You can smooth it with an emery board. Let it dry completely before you touch it.