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.
Thomas the Tank Engine is a fictional steam locomotive in The Railway Series books by the Reverend Wilbert Awdry and his son, Christopher. He became the most popular character in the series, and is the title character in the accompanying television spin-off series, Thomas & Friends.