Bob, Call me nuts, but I'm actually looking forward to the day I'll have a cataract removed for the very reason you mention, that experience of looking at the world, all of a sudden, *without* yellow filters. I read the same account as you described, in the color literature, that the sky takes on a stronger vivid shade of blue and so on. All I know about the Standard Observer is that it was made of two groups of men but I have no details on their age... I guess they had "normal color vision" 😊 / Roger -----Original Message----- From: colorsync-users <colorsync-users-bounces+graxx=videotron.ca@lists.apple.com> On Behalf Of Bob-BTY via colorsync-users Sent: Tuesday, January 14, 2020 10:42 AM To: colorsync-users@lists.apple.com Subject: Human color vision Many people don't seem to know that the lenses in the human eye start going yellow with age. By the age of 50 most people are looking at the world through yellow filters! I experienced this when having a lens replaced because of cataract. The new plastic lens was clear, and when I came out of the operating room, I could see that the dresses of the nurses (that were grey/white stripes before) were now blue/white when I looked at them with the new lens. With the yellow lens in my other eye they were still grey/white! A blue sky was now qite vivid with the new plastic lens, not so with the old yellow lens. I played about with Wratten filters to see how yellow my original lens was, but sadly I can't find the details any more, and nnow have two clear plastic lenses. I wonder how old the 'Standard Observer' was? Bob Frost _______________________________________________ Do not post admin requests to the list. They will be ignored. colorsync-users mailing list (colorsync-users@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/colorsync-users/graxx%40videotron.ca This email sent to graxx@videotron.ca