colour vision. the person may be able to see certain colours. however, there are many cases where there is no recovery. finally, a person with hemiachromatopsia see half of their field of vision in colour, and the other half in grey. the visual hemifield contralateral to a lesion in the lingual or fusiform gyrus is the one that appears grey, while the ipsilateral visual hemifield appears in colour. the variance in symptoms emphasizes the need to understand the architecture of the colour centre in order to better diagnose and possible treat cerebral achromatopsia.