Visual System Can Retain Plasticity, Even After Extended Early Blindness
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Deprivation of vision during critical periods of childhood development has long been thought to result in irreversible vision loss. Now, researchers from the Schepens Eye Research Institute/Massachusetts Eye and Ear, Harvard Medical School (HMS) and Massachusetts Institute of Technology (MIT) have challenged that theory by studying a unique population of pediatric patients who were blind during these critical periods before removal of bilateral cataracts. The researchers found improvement after sight onset in contrast sensitivity tests, which measure basic visual function and have well-understood neural underpinnings. Their results show that the human visual system can retain plasticity beyond critical periods, even after early and extended blindness. Their findings were recently published in the Proceedings of the National Advancement of Science (PNAS) Early Edition.
