Abnormal vision in childhood impairs brain functions: Study

Toronto: Children with abnormal vision are likely to have impairment in functions of brain areas responsible for things such as attention, a new study has found.

The researchers uncovered differences in how the brain processes visual information in patients with various types of lazy eye.

Lazy eye, known as amblyopia, is a loss of vision that originates in the brain, typically when a child develops an eye turn.

The unequal input causes the brain to ignore information from the weaker eye during brain development.

The findings demonstrated that the brain can divert attention away from a lazy eye when both eyes are open.

“One of the underlying reasons why some people with lazy eye have poor vision comes down to how the brain suppresses an eye,” said Amy Chow, a post doctoral student at the varsity.

“The poorer-seeing eye is open, the retina is healthy and sending information through to the brain, yet that information does not reach conscious awareness as the brain chooses not to use it,” Chow added.

The result shows that new treatments should also target higher-level processes such as attention, the researchers suggested.

For the study, appearing in the journal Investigative Ophthalmology and Visual Science, the team asked patients to pay attention to a specific set of dots among a group of distracting dots, all moving on a computer screen.

However, the tracked dots were only visible in one eye (the weaker eye) while the distracting dots were visible only to the other eye (the stronger eye).

The study revealed that people with both normal vision as well as anisometropic amblyopia, showing different images between the two eyes did not matter suggesting that both groups were able to overcome the distracting interference and track the dots successfully.

On the other hand, patients with lazy eye were unable to direct their attention to the target dots when they were visible only to the weaker eye.

The condition of lazy eye can be corrected in childhood, but treatment efficacy can vary highly.