Bad vision is not a tragedy these days. You can always wear glasses and there are certain surgical procedures that can fix your eyes up pretty well. However, bad vision should be addressed early in life, because, as this new study has shown, abnormal vision in childhood can affect the development of higher-level brain areas.
Information from the lazy eye gets ignored by the brain, which weakens it over time. Image credit: Lucashawranke via Wikimedia(CC BY-SA 4.0)
Scientists from the University of Waterloo, University of British Columbia, and the University of Auckland analysed patients with various types of lazy eye in order to see what are the differences in how the brain processes visual information. They found that brain diverts attention from the lazy eye when both eyes are open. This allows seeing more clearly through the good eye and being more aware of your surroundings. Current treatments for a lazy eye typically address the early stages of visual processing within the brain. However, scientists say that this research proves that new generation of lazy eye treatment should focus on higher-level brain areas responsible for things such as attention.
Lazy eye, known as amblyopia, is a vision loss that occurs in the brain. Typically it happens because eyes are not well-aligned and brain chooses to ignore information from the weaker eye. Unequal input from the different eyes results in less information than people with good vision receive. Scientists asked participants of the study to pay attention to a specific set of dots among a group of distracting moving dots. The dots that patients were asked to focus on, were only visible in the weaker eye, while the distracting ones were moving in the vision of the good one. People with healthy eyes had no problem tracking the dots despite the distraction. The same can be said about people with anisometropic amblyopia, but not the ones with strabismic amblyopia.
This research allows us to understand why people with lazy eye have an impaired vision. Amy Chow, lead author of this study, said: “One of the underlying reasons why some people with lazy eye have poor vision comes down to how the brain suppresses an eye. 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”.
Strabismic amblyopia, one of the main causes for a lazy eye, can be corrected in childhood, but procedure may not be entirely effective at preserving vision. That is why scientists say that lazy eye should be addressed in the brain – these kind of treatments would be more effective.
Source: University of Waterloo