What causes Hair and Eye Color to Change over Time? https://finallyhair.com/blog/ By Margaret Bryant https://sites.psu.edu/siowfa15/2015/10/15/did-your-eye-color-magically-change/

The Connection Between Hair and Eye Color Share a common pigment Melanin Produced by melanocytes http://pinbrowser.com/photo/475270566904415173

Melanin Types Shape Formula-C18H10N2O4 http://www.chemspider.com/Chemical-Structure.4884931.html Types Eumelanin-Provides brown and black pigment-when not abundant hair is blonde Pheomelanin- Found in hair and skin, provides pink and red Neuromelanin-found in brain, loss of it can result in neurological disorders Shape Formula-C18H10N2O4

Parts of the eye and melanin in eye Iris holds pigmented part of tissue Stroma Darkest eyes=more pigment Lighter eyes= less pigment More sensitive to sun http://www.clarksoneyecare.com/about-your-eyes/eye-anatomy-diagram.html

Changes in eye color Changes with melanin Sun Aging Diseases Melanin protects eyes from sun, but if exposed to UV rays too long, amount of melanin can change Aging Babies born with no melanin, gradually gain over time (by 1 year old) Some people increase or decrease in melanin over time Eye changes caused by genetics affect 15% of Caucasians Diseases Pigmentary Glaucoma- melanin shifts around eye Horner’s Syndrome- Disruption of nerve pathway http://www.skincareorg.com/eye-color/why-do-eyes-change-color-with-moods-age-and-surrounding/

Changes in hair Sun Aging Diseases Sunlight and UV rays kill melanin on dead cells (hair shaft) which makes hair lighter When hair grows, returns to normal color Aging Over time, the follicles that make melanin start to produce less, causing grey or white hair Some kids are born blonde and get darker with age The amount of eumelanin increases as one matures Diseases Osteoporosis- Premature grey hair (lower hormone levels) AIDS- stops hair follicle activity which Vitiligo- Death of melanocytes, so no pigment

What are the most common hair colors in the world? Black is most common due to eumelanin Brown is common Blonde=2% Red hair=1% http://www.florabac.com/mainpage/detail/what-is-the-most-common-hair-color

Citations "Anatomy of Your Eye." - Parts of the Eye Explained. Clarkson Eyecare, n.d. Web. 20 Sept. 2016. Robertson, Sally. "What Is Melanin?" News-Medical.net. AZO Network, 08 Sept. 2014. Web. 20 Sept. 2016. Rubin, Holly. "SiOWfa15: Science in Our World: Certainty and Controversy." SiOWfa15 Science in Our World Certainty and Controversy. Word Press, 15 Oct. 2015. Web. 21 Sept. 2016 "Eye Colors: What Gives Eyes Their Color?" Eye Color. Vision Service Plan, 2016. Web. 21 Sept. 2016. Gutierrez, D. M. "Why Does the Sun Make Your Skin Darker But Your Hair Lighter?" LIVESTRONG.COM. LIVESTRONG.COM, 24 Oct. 2013. Web. 21 Sept. 2016. Laura J. Martin, MD, MPH, ABIM Board Certified in Internal Medicine and Hospice and Palliative Medicine, Atlanta, GA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team. Castro, Jseph. "Why Do Some Blond Kids Go Dark?" LiveScience. TechMedia Network, 29 May 2013. Web. 21 Sept. 2016. Lee, Lexa W. "Why Some Diseases Cause Your Hair Color to Change." EHow. Demand Media, n.d. Web. 21 Sept. 2016. Boeree, C. George. "Race." Race. N.p., n.d. Web. 21 Sept. 2016.