1. What causes Hair and Eye Color to Change over Time?
By Margaret Bryant

2. The Connection Between Hair and Eye Color
Share a common pigment
Melanin
Produced by melanocytes

3. Melanin Types Shape Formula-C18H10N2O4
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

4. 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

5. 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

6. 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
Vitiligo- Death of melanocytes, so no pigment

7. 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%

8. How it relates to me
I have hair and eyes and my hair has changed a lot since I was born, along with my eyes changing from blue to green.

9. Citations
"Anatomy of Your Eye." - Parts of the Eye Explained. Clarkson Eyecare, n.d. Web. 20 Sept
Robertson, Sally. "What Is Melanin?" News-Medical.net. AZO Network, 08 Sept Web. 20 Sept
Rubin, Holly. "SiOWfa15: Science in Our World: Certainty and Controversy." SiOWfa15 Science in Our World Certainty and Controversy. Word Press, 15 Oct Web. 21 Sept. 2016
"Eye Colors: What Gives Eyes Their Color?" Eye Color. Vision Service Plan, Web. 21 Sept
Gutierrez, D. M. "Why Does the Sun Make Your Skin Darker But Your Hair Lighter?" LIVESTRONG.COM. LIVESTRONG.COM, 24 Oct Web. 21 Sept
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 Web. 21 Sept
Lee, Lexa W. "Why Some Diseases Cause Your Hair Color to Change." EHow. Demand Media, n.d. Web. 21 Sept
Boeree, C. George. "Race." Race. N.p., n.d. Web. 21 Sept