To investigate the effects of visual defect on the reading and psycholinguistic processes, results were obtained for partially seeing children (grades 1 to 4, mean IQ 100) on the Monroe Reading Examination, Gates Speed and Accuracy Tests, Illinois Test of Psycholinguistic Abilities (ITPA), and Stanford-Binet Intelligence Scale. Reading scores were (1) below grade level for grade 4 and at grade level for grade 3, (2) lowest on oral reading and highest on the Gates comprehension tests, and (3) below average for mental age, grade placement, and reading speed, but higher than average in accuracy. IQ was related positively with reading in relation to grade level, but negatively with reading in relation to mental age. The subjects made no excessive errors of any kind; error types and the degree of visual defect did not differ significantly. However, children with refractive defects read less well than the other subjects. On the ITPA, the subjects performed significantly less well than normals n visual decoding, motor encoding, visual-motor sequential, and visual-motor association subtests, but did not differ on the auditory-vocal channel subtests. ITPA performance was related to eye condition only through the indirect effect of visual acuity. Reading achievement was positively correlated with the three ITPA subtests at the automatic-sequential level. Eight figures, 12 tables, four case histories, and 32 references are provided. (JD)