Ultraviolet converter

An ultraviolet converter was a device on Sea Base 4 that converted normal light into ultraviolet. (PROSE: Warriors of the Deep) The Fifth Doctor fired ultraviolet rays at the Myrka, killing it due to the Myrka's lack of tolerance to UV rays. He later used the ultraviolet converter to blind Nilson, saving Tegan Jovanka's life. (TV: Warriors of the Deep)