Using pepper spray is a legally-defensible less-than-lethal use of force. Pepper spray is carried by LEOs who use it all the time, so there's lots of court cases where its use has been defended.
If wasp spray to the eyes causes any sort of lasting damage to the perp, be prepared for a lawsuit that will take away everything you have. You would have been better off to have shot him, especially if you're in a Stand Your Ground state.
Wasp spray for self defense is a bad idea. It is a myth! Stick with the Pepper Spray. Wasp spray is unproven and has never been tested on humans. Wasp Spray will NOT work on those who cannot feel pain i.e. drugs or alcohol. Pepper Spray is an inflammatory which will cause the eyes to slam shut no matter the situation. That’s why over 40,000 law enforcement agencies carry it nationwide and even the smallest canisters will fire 10 ft while the larger canisters will fire 25 to 30 ft.