If it's any consolation, all little ones do this.
They grab at what ever is available because they are exploring the world around them, and yes they have a disproprtionately strong grip, and yes it hurts!
The way round it is to be quick when he reaches for your face or hair. Cup your hand around his so he can't grab you, and push his hand away gently but firmly. At the same time, make eye contact with him and say "No!" in a firm, buit not shouted voice, and keep eye contact with him with a stern expression for as long as you can.
It takes loads of patience, but if everyone does it every time, he will get the message.
As soon as he stops grabbing when you say "No!" without the need to hold his hand, praise lavishly with kisses and smiles.
All babies need training in social behaviour - this is just one more aspect of that. I wouldn;t be inclined to go down the 'ignoring' route at this age. He is too young to equate his behaviour with a punishment, so he won't learn the lesson you want to give him, he will simply be distressed when you withdraw from him and he doesn't understand why.
It does work - I speak as a specs. wearer with two grandchildren, and another one on the way!