The clear shells are made from virgin ploycarbonate and should be stronger than the black ones as they can use old used ploycab for them thats why the black ones are cheeper.
As the material has been processed befor it is not as strong.
The other problem is they were made for america and there 9volts are about 2 mm smaller than ours dont ask me why they just are.
but hermit man just get a halo .
give me a ring and ill sort you boys out.
And yes if a ball breaks in side the eyes are a pain to clean so just use good paint..