Abstract
M.Phil. (Optometry)
The purpose of this study was to determine the prevalence of vision deficiencies in the children from the schools of the learning disabled compared to the children from the mainstream schools. One hundred and twelve (N = 112) children from the two learning disabled schools and eighty (N = 80) children from the mainstream school, in Johannesburg had their vision assessed. The evaluation of functional vision included visual acuity (Snellen Acuity), refractive status (Static Retinoscopy), ocular health status (Internal and External evaluations), accommodation (Monocular Estimate Method (MEM), ±2.00D Flippers, Donder's push up method), binocularity (Cover Test, Vergence Facility, Smooth Vergences, Near Point of Convergence (NPC) and ocular motilities
(Direct Observation). The results of this study revealed a significant relationship of poor vergence facility (Cramer's V =0.369); lead of accommodation of the right (Cramer's V = 0.379) and left eye (Cramer's V= 0.386); poor amplitude of accommodation of the left eye (Cramer's V=0.316) and the mainstream group. A significant relationship was
found between the learning disabled group and poor saccadic accuracy (Cramer's
V=0.343) and a high lag of accommodation of the right (Cramer's V= 0.379) and
the left eye (Cramer's V= 0.386). Both the learner groups in the current study
present with different visual deficiencies, and thus comparisons in terms of
prevalence is complicated. It will be erroneous to say one group presents with a
high prevalence of visual deficiencies than the other nor to conclude that the
prevalence of visual deficiencies is the same in both groups. The results of this study provide further support for full vision screenings (including visual integrity pathway, and visual efficiency skills) to be routinely done in both mainstream and schools for the learning disabled.