Magnitude of refractive errors and low vision among Braille-reading children in Nigeria

Purpose: To examine Braille-reading children and establish the magnitude of refractive errors and low vision as a cause of visual disability. Methods: Using the WHO definition of low vision and standardized methodology, 205 Braille-reading children (mean age <17 years) were examined in five schools for the Blind, four integrated schools, and one rehabilitation project in the Northern, Middlebelt, and southern parts of Nigeria. Causes of blindness and low vision were classified anatomically and avoidable causes were identified. Refraction and low vision assessment were carried out to ascertain best-corrected visual acuities and visual acuities after the application of low vision devices. Results: Entry (presenting) visual acuity measurements showed that 30.7% (n = 63) were totally blind, 66% (n = 135) had low vision, and 1.45% (n = 3) had normal vision. The major causes of visual impairment were corneal 33.7% (n = 69), lens 24% (n = 49), retinal 9.3% (n = 19), glaucoma 11.2% (n = 23), optic nerve 9.3% (...