A mother in Tennessee is thankful Facebook helped her discover a rare disease in her toddler.Two of Tara Taylor's friends urged her to get her 3-year old daughter Rylee checked by a doctor because her eye appeared to be glowing in a picture she posted. Taylor said there was no indication her daughter was having trouble seeing, but she took her to the doctor anyway. Sure enough, Rylee was diagnosed with Coats' Disease. It's a rare condition that causes vision loss. Rylee will now have the proper treatment for her condition, all thanks to social media.