Calcium deficiency?

Wow! All I can say is inspect the underside of the leaves for any sign of insects.
Is this all of your peppers or just one plant?
If it were a fungal type disease, usually they start at the bottonm leaves and work their way up..hard to tell from your pics, but it looks all over to me?
Have you had cold snaps in the last couple of weeks?..Could be cold damage.
Or...did you fertilize heavily recently?

9 times out of 10 it is caused by herbicide exposure. Even the slightest drift of it on the wind can cause this.

The one time out of 10 that it isn't herbicides it is caused by a severe infestation of aphids on the underside of the leaves.

Dave