Brothers Spencer and Tyler Vanscyckle (IMAGE) UT Southwestern Medical Center Caption Brothers Spencer Vansyckle, left, and Tyler Vanscyckle have the rare genetic disease X-linked reticulate pigmentary disorder, which makes their eyes especially sensitive to sunlight. Credit UT Southwestern Medical Center Usage Restrictions With credit line License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.