I had a look at the wikipedia Bungee site and eye issues (and other things) can be caused after a succesful jump. The things that can happen after an unsuccessful jump are more obvious.
Walking or running might be alternatives for charity fund-raising. So might a tea party, bring-and-buy sale or Bridge afternoon. Many charity websites have lots of ideas and this one certainly does: www.astrofund.org.uk/
Army horses loose on London streets