Slack jokes

My friend: Hey, why are you always smiling?

Me: 'Cause life is a joke and we’re all slacking it off.

So why don’t blind people go sky diving? It scares the hell out of their seeing eye dog.

When does a blind person know when he’s about to hit the ground? The leash goes slack.

How does a blind person know when a skydive has finished?

The dog lead went slack.