What do you have to hand now?

[Jonas]

I don't know if this would be available in the UK, but over here we have aerosol cans of "wasp and hornet" spray which shoot a stream (not a spray) of very toxic liquid about 10 to 15 feet. Whomever you hit in the eyes with this stuff will be permanently blinded unless he/she gets immediate professional medical treatment. Naturally, if you all had this stuff handy and some thug broke into your house to do you harm, after spraying the goon's eyes it you'd immediately call an ambulance...