Visual acuity in preschool children: the Chapel Hill-Durham Day-Care Vision Study.

Between 1985 and 1987, 1362 preschool children attending 45 day-care centers in Chapel Hill and Durham, North Carolina had their visual acuities tested by matching HOTV opto-types. Study participants were comprised of 718 males and 644 females. Seven hundred eight were African Americans, 607 were white, and 47 were from other ethnic groups. The children's ages were 89 < 3 years, 496 = 3 years, 531 = 4 years, and 246 > 5 years old. Only 69 children (5.1%) were unable to have their visual acuity tested in both eyes. Although there was no association between testability and either race or gender, there was a strong association with age, with 65 of the 69 children (94.2%) not testable being < 4 years old. Further, there was a clear relationship between visual acuity and age. The 1293 participants (2586 eyes) whose visual acuity was measured successfully in both eyes revealed that 2471 eyes (95.4%) had visual acuities of 20/40 or better. There were significantly more African Americans (56 or 8.4%) than whites (23 or 4.0%) in the 20/40-1 to 20/100 category.