There is a three part aritcle re the vision of animals and in particular trout. The author explains the potential trigger points of UV light. You will find this thought provoking. Wow, think of all the grizzly utilized and I bet partridge isn’t much better. Ginger is worth an investment and experiment it appears. Very nice site and this type of article is unique in its’ ability to make one think about our pasttime.  http://overmywaders.com/cblog/