The PupIlommetry and NorEpinephrine study uses non-invasive methods to evaluate a potential neural mechanism for dyslexia - abnormal signaling in norepinephrine, which is a chemical messenger in the brain. This signal is important for learning and memory as well as detecting surprising and unexpected events. We are recruiting children 7-12 years old who are typical readers, with dyslexia, and those with dyslexia and ADHD.