WFMZ-TV reports the accident happened around 7:20 a.m. at 2nd and Penn streets, at the foot of the Penn Street Bridge, in downtown Reading.
The person in the wheelchair had a red light, but started to cross the street anyway, police said.
They said the truck had a green light and started to go. The driver told police he didn't see the wheelchair because of sun glare.
The person in the wheelchair was thrown 24 feet from their wheelchair.
The pedestrian was transported to the hospital.
There was no information on the victim's identity or condition.