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Updated: Apr 28, 2026

A Method to Quantify Visual Information Processing in Children Using Eye Tracking
Published on: July 9, 2016
Refractive error and visual impairment in private school children in Ghana
Ben D Kumah1, Anne Ebri, Mohammed Abdul-Kabir
1*OD, MSc †PhD ‡MGCPS, MBBCh ∥FWACS **MPH, PhD Kwame Nkrumah University of Science and Technology (BDK, MA-K, A-SA, NYK, SA, AAi, AAm, SL), Kumasi, Ghana; Brien Holden Vision Institute (AE, KN), Durban, South Africa; and African Vision Research Institute (AE, KN), University of KwaZulu-Natal, Durban, South Africa.
Purpose:
To assess the prevalence of refractive error and visual impairment in private school children in Ghana.
Methods:
A random selection of geographically defined classes in clusters was used to identify a sample of school children aged 12 to 15 years in the Ashanti Region. Children in 60 clusters were enumerated and examined in classrooms. The examination included visual acuity, retinoscopy, autorefraction under cycloplegia, and examination of anterior segment, media, and fundus. For quality assurance, a random sample of children with reduced and normal vision were selected and re-examined independently.
Results:
A total of 2454 children attending 53 private schools were enumerated, and of these, 2435 (99.2%) were examined. Prevalence of uncorrected, presenting, and best visual acuity of 20/40 or worse in the better eye was 3.7, 3.5, and 0.4%, respectively. Refractive error was the cause of reduced vision in 71.7% of 152 eyes, amblyopia in 9.9%, retinal disorders in 5.9%, and corneal opacity in 4.6%. Exterior and anterior segment abnormalities occurred in 43 (1.8%) children. Myopia (at least -0.50 D) in one or both eyes was present in 3.2% of children when measured with retinoscopy and in 3.4% measured with autorefraction. Myopia was not significantly associated with gender (P = 0.82). Hyperopia (+2.00 D or more) in at least one eye was present in 0.3% of children with retinoscopy and autorefraction.
Conclusions:
The prevalence of reduced vision in Ghanaian private school children due to uncorrected refractive error was low. However, the prevalence of amblyopia, retinal disorders, and corneal opacities indicate the need for early interventions.
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