You’re not Wolverine. Stop caring your keys like this for self-defense.

Why doesn’t this work. The idea is that you hit the person in the eyes with your keys. The problem is the human eye is small and is surrounded by a thick bony structure called the skull. Being small target to aim for; that is probably moving. A pro boxer would be hard pressed to throw punches that accurately. The other problem is that it hurts your hand. Don’t believe me, go to a solid wall that doesn’t scratch easily (a brick wall works well). Hold your keys like this and slowly press them into the wall and see how it feels.

Instead carry your keys like this.

By taking one key between your thumb and index finger, you create a solid foundation for the key to work as a self-defense tool.  Try the same drill against the wall and see how much more pressure you can applying.  Now the key works as a sharp metal object to help you defend yourself.