It was once a useful item, most people always used carry one of these in their belt, so they could save mana in their hunts because they didn't need to cast light spells. High levels tend to use Frozen Starlights since they're an infinite source of blue light. However, since the ambient light was implemented, torchs were left behind, and are almost completely useless now.
As the torch is used, its weight changes to 4.50 oz, 4.00 oz and 3.50 oz.
Some people use programs called Light Hacks, of course, this is against Tibia Rules and they may get Banished. They are not used as much nowadays due to the ambient light update.