Finally tonight the story of a man who found meaning in darkness in this story from

kPBS's kory Suzuki and Carolyn Corellis we visit the Tijuana River Estuary in Southern California where a volunteer is leading a tour that encourages visitors to experience nature a little differently.

Good question. Yes, this is lemonade berry.

And the reason I know it's lemonade berry is because the leaves are thick and leathery, almost

like the tongue of a leather shoe. I've learned to identify about

almost 40 plants just by touch and also smell.

All right, Digit. Here we go. My name is Ron Peterson. I'm 73 years old. I'm a retired scientist and engineer.

I live here in Imperial Beach and I am blind.

And we are here at the Tijuana Estuary.

This is one of my homes away from home.

There's several nature walks and there's several bird walks.

And one of those nature walks is mine.

I'm a docent for this nature walk

called the eye-opening experience without sight.

Where a blind person leads a nature walk and introduces visitors to the native plants with the emphasis on the other four senses besides site.

Well let's start over here with a very special plant right over here.

Everyone take a whip and tell me what you think.

I don't love it.

Oh, because we haven't. I don't love it.

Most people don't care for it all that much.

And this plan is actually called Bladder Pod, and I think you can see why it has the name Bladder Pod.

One reason I know this is Buckwheat is I could see as I've worked here as a volunteer for about

...