At approximately 4PM eastern time, after having an eye doctor appointment in Allentown, PA for a check up, I noticed an object. It was east of my position at 11 0'clock and about 30-35' off the horizon. At first I thought it was a kite but I realized it was way higher than a kite would have been flown. It had a sort of pulsating light, or reflecting of the sun that made it seem like it was pulsating or flashing. It would get brighter and then dim down to almost nothing. Then return to the brightness again. It also didn't seem to be moving at all. If it was a weather ballon I think I would have detected some sort of motion but I didn't see any. This went on for about 10 minutes until I couldn't see it pulsating anymore.