The importance of vision in early infancy

New study provides evidence that the brains of blind infants develop differently

Infant with congenital cataracts

The importance of treating congenital cataracts early is highlighted in a new neurological study on teens and adults whose sight was restored.

The international team of researchers tracked the brain patterns of 12 individuals, an average of nine years after they had the dense, congenital cataracts in both eyes removed, restoring their sight. These patients were only able to perceive light before they underwent surgery.

The study, published in the journal Scientific Reports, found a distinct reduction in the alpha waves of the brain of the congenital cataract group, when compared to two control groups – a normal-sighted group and another with people who had visual impairment, but no history of total blindness.

The researchers speculate that the infant brain has a ‘sensitive period’ during which normal alpha wave brain activity is developed. Prior studies in animals support the theory that this sensitive period exists, the paper noted.

Yet the study team believes that a little sight went a long way, explaining in the paper: “We demonstrate that the – though limited – patterned visual input available to individuals with a history of congenital but incomplete cataracts was sufficient to set up the neural mechanisms for alpha [wave] generation, and thus the neural mechanisms important for the control of visual cortex activity.”

The alpha wave state is believed to coordinate the brain when it is undertaking a variety of perceptual and cognitive tasks.

However, the study did find that the theta brain waves of the congenital cataracts group did adapt following cataract removal to match the patterns seen in the two control groups.

Image credit: Centre for Disease Control and Prevention