Sun Castle

I went to the optician the other day. Appointments are normally quite expensive, but this particular optician appeared to be reasonably cheap.
Anyway, he asked me if I’d just come for a check-up, or was there anything specifically that I was having trouble with. So I told him that I was having a bit trouble seeing distances.
“Okay,” he said, “Step outside a minute and we’ll see how bad it is.”
I followed him outside and he pointed to the sun.
“What’s that up there..?” he asked.
“It’s the sun,” I replied.
“Well,” he demanded, “how much bloody further do you need to see..?”
… :o/