For children in their early years, visual acuity – the acuteness or clearness of vision - is used as a proxy for brain development measurement.

Why is this so?

This is because the retinal (eye) and brain cells develop from the same cell sources in the fetus. Hence, better visual development in early childhood reflects better development progression of the brain (see interactive demo).

Such young children are not asked to read eye charts. Rather, visual acuity is measured using Teller Acuity Cards and Visual Evoked Potentials (VEP) methods¹. Both methods are used in clinical research settings to gauge the acuteness or clearness of vision, a proxy to the child’s brain development in response to the different diet and/or stimulation studied.

Visual acuity is accepted as the best non-invasive method of determining the level of brain development.