How Does Colorblindness Work? @BrainStuffShow

Uploaded July 2015 | Updated September 2026, 1 week ago

We see color thanks to complex coordination of signals from the eyes to the brain. Here's what happens when the signal gets scrambled.

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health.howstuffworks.com/human-body/systems/eye/colorblindness.htm

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SOURCES:

ghr.nlm.nih.gov/gene/OPN1LW

ncbi.nlm.nih.gov/books/NBK1301

medical-dictionary.thefreedictionary.com/tritanomaly

enchroma.com/technology

smithsonianmag.com/innovation/scientist-accidentally-developed-sunglasses-that-could-correct-color-blindness-180954456/?no-ist

ghr.nlm.nih.gov/condition/color-vision-deficiency

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$Can I Get My Face On Currency? Forget the normal 15 minutes of fame – the real ticket to immortalizing your legacy is to get your face on currency. But how does it work? Join Cristen to learn more. Learn more at HowStuffWorks.com: http://money.howstuffworks.com/currency.htm Share on Facebook: https://goo.gl/bqBBey Share on Twitter: https://goo.gl/eHi0An Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com Hey BrainStuff, it’s me, Cristen. Throughout history, civilizations have immortalized their most important individuals in numerous ways. But in the modern age, one of the most legit ways to become historically significant – to ascend beyond the middling, forgettable fame of the average celebrity – is to have your face on the money. But who decides how people get their picture on currency, anyhow? Could you do it? Let’s tackle the first question. In the US, the answer is surprisingly simple. The current Secretary of the Treasury is responsible for deciding whose mug goes on which bill. That’s it, essentially. “But wait”, you might say, “Cristen! We’ve had the same famous folks on US currency since 1929”. And, well, you’re right. In 1929, a treasury committee selected the current countenances based on their “permanent familiarity in the minds of the public.” Which, when you think about it, sounds like a little bit of a self-fulfilling prophecy. But, anyway, we’ve more or less stuck to our guns on that initial decision. See, although the bills have been redesigned multiple times, the government has also been very hesitant to rock the portrait boat. This wasn’t always the case. Before 1929, the US had already built a long and storied history of paper bills. It dates back to 1690, when the Massachusetts Bay Colony issued their first paper money. A long, convoluted history led us to the 1929 decision. But let’s pause the history for a second, and answer the second question: Can you be on US currency? Well, no. Not if you’re watching this video. Between 1690 and 1929, there was only one hard and fast rule added to the process: no living person may be depicted on currency. Unfair? Yeah, tell me about it. Five people have appeared on US currency while they were still alive, but the guy who ruined it for everybody was named Spencer M Clark. He was promoted to Superintendent of the National Currency Bureau in 1862. In 1864, Clark’s office was charged with producing a series of fractional currency notes. The details of the story differ, but regardless of whether you think it was an honest miscommunication or one man’s shameless shot at the ultimate ego trip, one thing’s for sure: Spencer Clark plopped his face on the 5-cent note. And, as you can imagine, Congress was pretty cheesed off. They immediately retired the note and made the no-living people rule. So, thanks, Spence, for being one of the worst party-poopers in the history of money. In 2015, Secretary of the Treasury Jack Lew made a declaration as bold as Spencer Clark’s (though not as self-absorbed). He noted that the ten dollar bill was going to be redesigned for a number of factors, and that the treasury was taking the opportunity to put a new face on the bill, replacing Alexander Hamilton. Seeking input from the public, Lew asked for submissions that meet the following conditions: 1. The nominee must be a woman. 2. She must be deceased, and 3. The nomination must revolve around the theme of democracy. Secretary Lew asked people to use the hashtag #TheNew10 to submit their ideas online, and you can see his official announcement on YouTube. I have to ask: who do you think should be on the $10 bill? Let me know in the comments below – oh, and fun fact: this won’t be the first woman on US currency. Sacagawea, Helen Keller and Susan B. Anthony have all appeared on circulating US coins. Martha Washington and Pocahontas have also both appeared on paper currency – silver certificates and bank notes, respectively. SOURCES: Jack Lew, Secretary of the Treasury on the redesign of the $10: https://www.youtube.com/watch?v=hFrc25f_mUc https://thenew10.treasury.gov/ BBC: http://www.bbc.com/news/blogs-magazine-monitor-28591592 http://www.newmoney.gov/currency/history.htm http://money.cnn.com/2015/06/17/news/economy/woman-on-ten-dollar-bill/ http://www.treasury.gov/press-center/press-releases/Pages/jl0079.aspx http://www.washingtonpost.com/business/get-there/gaining-currency-a-woman-will-be-the-face-of-the-10-bill/2015/06/19/1b3b7528-1443-11e5-89f3-61410da94eb1_story.html http://www.executivecurrency.com/owners/ http://papermoneyguide.com/faq.htm$

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