Inability or decreased ability to see colour, or perceive colour differences, under normal lighting conditions
American Medical Association complete medical encyclopedia : American Medical Association : Free Download, Borrow, and Streaming : Internet Archive
https://archive.org/details/americanmedicala00amer
Web
2003
Color Blindness | National Eye Institute
https://nei.nih.gov/health/color_blindness/facts_about
Colour vision deficiency (colour blindness)
https://www.nhs.uk/conditions/colour-vision-deficiency/
October 18, 2017
New documentary uncovers the Irish links to America's Tipperary Hill
Aoife Barry
http://www.thejournal.ie/tipperary-hill-radio-documentary-3063059-Nov2016/
The Story Behind Syracuse's Upside-Down Traffic Light
https://gizmodo.com/the-story-behind-syracuses-upside-down-traffic-light-1545301615
March 17, 2014