Due to the emissions released from the Darwin Gun it was necessary to acquire a set of safety goggles so that continued and prolonged use of the gun would not result in any unwanted blindness or possible worse. The critical factor was to reduce the blue aura emissions from the primary discharge stream and for this a primary lenses was selected that has optical properties in the opposite end of the spectrum.
I came across an article in a book written by Dr George Rolleston a professor of Anatomy and Physiology at Oxford University who in an article published 30th May 1860 describes a way to greatly influence human behavior by electrical stimulation.