Nothing is complicated compared to brain surgery. It’s incredibly dangerous, delicate work where in one slip up can ruin someone’s life irreversibly. The procedures have come a long way, and these days, while still risky, it’s generally a very safe process to undergo. But back in the day, when they were still figuring it out, you would not have wanted to be one of the human guinea pigs.

Here are some of those unfortunate souls that underwent brain surgery when we still didn’t even fully understand how a brain works. Some of these photos are truly haunting. There are crazy scars, tumors, and afflictions that just glimpsing at will give you a headache. There are some positive moments too, like post-surgery success photos of people who look like all the pressure has been let out of their heads like a balloon. 

But overall, these are some gnarly images that make us grateful to live in modern medical times.