This document discusses different types of reading disabilities including dyslexia, hyperlexia, and alexia. Dyslexia is a learning disability affecting decoding, comprehension, and fluency. Hyperlexia is a superability in reading beyond one's age and IQ. Alexia is acquired dyslexia from brain damage. Decoding difficulties are at the root of most reading disabilities. Signs include issues with sounding out words and reading fluency. Comprehension and retention problems also impact reading ability. The document provides information to design remedial reading programs tailored for specific disabilities.