Met many guys that thought they could win against skilled opponents by ball grabs, bites and eye gouges. Part of the arsenal but if you're going to go medieval it will release the dog in a skilled fighter. A real eye opener for guys that have never really fought anyone is to go to a jui jitsu school for a day or get in the ring in boxing. It will really hurt the ego as you're easily beaten almost effortlessly. Seen it happen time and time again. One stood out in my memory. When I was in jui jitsu a 260lbs guy came in for his first lesson. Grappling with a 140lbs guy he was very quickly tapping time and time again. I saw it in his face. He was humiliated. Never saw him again. It was his first and last day.
Anybody not skilled in a particular art who goes to a "school" for the first time and abides by the "rules" will be beaten by a skilled practitioner of that school.
Doesn't matter if it's bjj, karate, boxing, whatever.
The reason is you are bound by the "rules" of that art while in the school.
I took Kyokushin karate. There is no hand strikes allowed to the head.
What "rules" are set down in a local bjj school?
Have you ever been poked in the eyes or kicked in the balls?
You are incapacitated.
To say by doing this you will then be subject to the same is irrelevant if you get in the first accurate strike.
Are you going to not use an eye strike and let a skilled bjj fighter beat you up in a real fight because you are afraid he might also poke your eye?
Are you not going to bite his finger off or fish hook his face because he might then do the same?
Is this the Marquis of Queensbury street fighting rules?
Go to your son-in-law's bjj school and go on the mat with him. Don't tell him you are going to put his eye out.
Drive your finger into his eye socket right away unexpectedly. See what happens.
He will be incapacitated. He will be in shock with his eyeball wrecked.
Then you can run away or break his knee and bring him down and start kicking him in the head.
Do you think he will run after you with his eye hanging out?