Yes, the visual cortex is plastic, even in adults:
We measured adaptation in the responses of populations of cat V1
neurons to stimulus ensembles with markedly different statistics of
stimulus orientation. We found that adaptation served two homeostatic
goals. First, it maintained equality in the time-averaged responses
across the population. Second, it maintained independence in
selectivity across the population.
http://www.nature.com/neuro/journal/v16/n6/full/nn.3382.html
Plasticity is invoked for encoding information during perceptual learning, by internally representing the regularities of the visual environment, which is useful for facilitating intermediate-level vision--contour integration and surface segmentation. The same mechanisms have adaptive value for functional recovery after CNS damage, such as that associated with stroke or neurodegenerative disease. A common feature to plasticity in primary visual cortex (V1) is an association field that links contour elements across the visual field. The circuitry underlying the association field includes a plexus of long-range horizontal connections formed by cortical pyramidal cells. These connections undergo rapid and exuberant sprouting and pruning in response to removal of sensory input, which can account for the topographic reorganization following retinal lesions.
http://www.ncbi.nlm.nih.gov/pubmed/22841310