While most of us are limited to the visible spectrum, people with a condition called aphakia possess ultraviolet vision. Aphakia is the lack of a lens, due to surgical removal for cataracts or congenital defects.
A railroad lantern and a railroad lamp are two different things. Lanterns were designed to be portable (i.e. carried) and were basically globes surrounded by a metal frame with a fuel source. When you think of a railroad worker swinging a signal, think lantern.
The Log Tunnel is a destination based on the log tunnel on Misty Island, made up of two pieces. The tunnel is an old tree stump hollowed out to let engines pass through. It is similar to the Quarry Mine Tunnel, where engines can go up the track and appear at the other end of the tunnel. There is also a section for engines to pass through the side of the tunnel. A Finish Line variant of the Log Tunnel is available as an exclusive part of the Dustin Comes in First Train Set. It lacks the gap in the bottom that allows a train to run underneath, and it has a wood panel with people painted on it that pops out when an engine goes through the end of the tunnel.