This document discusses various physical, physiological, and perceptual factors that can affect reading. It identifies several intrinsic factors like cognitive deficiencies, vision problems, hearing issues, and attention disorders that can negatively impact reading. Specific visual defects like myopia, hyperopia, and astigmatism are examined. Auditory issues are explored, outlining effects on vocabulary, sentence structure, speaking, and academic achievement. Perceptual factors like self-concept, beliefs, expectations, needs, and tendencies are also summarized as internal influences on perception and reading. The document provides educational implications of addressing issues like lighting, font size, and screening to support students.