Enemies don't stop shooting just because you are invisible... as a well seasoned hunter, I can speak to that. They will often shoot at the last location they could see you at. Therefore if you don't move or only run towards them/away from them in a straight line, there is a good chance you will get hit. Also if you are soloing the lamp section of CE, you have to be really careful when getting hit by the thrall. There is often a hoard of them following you, so you need to isolate one from the group (run around the lamp a couple times) before letting one hit you, otherwise they will all attack you at the same time, which results in like ten melee hits simultaneously.

You can't just stand there, the enemy will auto-attack the last place you were standing if they still register an impact. When you go invisible, jump out of melee range and run.

If an enemy is already in the process of attacking you or about to then they'll continue through with it even if you're invisible.

Move

Dont stand in one place then

Outside of the beginning of ce they are pretty useless. Lightswitch also makes them along with any melee skill outside of throwing knives a automatic death sentence.