Visual acuity and early literacy at 6-7 years: A reduction in visual acuity is associated with decreased reading efficiency in school children

Publication authors

Bruce A.; Wright J.; Chambers B.; Barrett B.T.; Bloj M.; Sheldon T.


Purpose: Reduced visual acuity in young children potentially affects their long term educational attainment, health and social outcomes. This prospective, cross-sectional study, nested within the Born in Bradford birth cohort, examines the association between reduced visual acuity and reading efficiency at age 6-7 years.

Methods: On school entry (4-5 years), 886 children (of whom 400 had failed their vision screening, visual acuity (VA) >0.2 logMAR in one or both eyes) were recruited. Visual acuity (VA) and literacy (Woodcock Reading Mastery tests; letter and word identification) were measured annually over a three year period. VA was tested by an orthoptist or optometrist, monocularly at three metres to threshold using crowded logMAR. The bestmeasured VA recorded with glasses or pinhole, was used in the analysis as the visual acuity measure. A test of reading efficiency (TOWRE2) was introduced in year three of the study (6-7 years); this measures the number of words read correctly in 45 seconds. Consisting of two subtests, printed words and phonics, TOWRE2 was administered on the same day as the vision assessment. The primary outcome measure was reading efficiency (standardised for age). Multilevel logistic regression was undertaken, adjusting for factors reported in the literature to be associated with educational attainment, namely cognitive ability, ethnicity, socio-economic status, early life and maternal life-style.

Results: In year three (age 6-7 years), 504 children remained in the study and 460/504 (90%) had a recorded VA and had completed TOWRE2. The reading efficiency score reduced by 3.03 points for every 1 line (0.1 OlogMAR) reduction in VA (95% CI -4.39 to-1.66, p<0.001). When adjusted to account for cognitive ability, demographic factors or socioeconomic factors, the impact of VA remained statistically significant in the multivariable model with the score reducing by 2.25 points (95% CI-3.65 to -0.86, p=0.002) for every 1 line reduction in VA.

Conclusions: Reduced VA was associated with a decline in reading efficiency. Longitudinal analysis of the vision and literacy measures over the three years will provide data on the impact of treatment for reduced vision on developing literacy and future educational attainment.