ologist ▁Daniel ▁Good man . ▁May ▁had ▁a ▁stem - cell ▁trans plant ▁in ▁his ▁right ▁eye ▁in ▁ 2 0 0 1 ▁when ▁he ▁was ▁ 4 3 , ▁after ▁ 4 0 ▁years ▁of ▁blind ness . ▁He ▁reported ly ▁has ▁adapted ▁well ▁to ▁his ▁recovered ▁vision . ▁May ▁still ▁has ▁no ▁intuit ive ▁grasp ▁of ▁depth ▁per ception . ▁As ▁people ▁walk ▁away ▁from ▁him , ▁he ▁perce ives ▁them ▁as ▁literally ▁shr inking ▁in ▁size . ▁He ▁has ▁problems ▁distingu ishing ▁male ▁from ▁female ▁faces , ▁and ▁recogn izing ▁emot ional ▁expressions ▁on ▁un famil iar ▁faces . ▁ ▁The ▁effect ▁of ▁visual ▁loss ▁has ▁an ▁impact ▁in ▁the ▁development ▁of ▁the ▁visual ▁cor tex ▁of ▁the ▁brain . ▁The ▁visual ▁imp air ment ▁causes ▁the ▁oc cip ital ▁lo be ▁to ▁lose ▁its ▁sens itivity ▁in ▁perce iving ▁spatial ▁processing . ▁ ▁S ui ▁and ▁Mor ley ▁( 2 0 0 8 ) ▁proposed ▁that ▁after ▁ 7 ▁days ▁of ▁visual ▁dep riv ation , ▁a ▁potential ▁decrease ▁in ▁vision ▁may ▁occur . ▁They ▁also ▁found ▁an ▁increasing ▁visual ▁imp air ment ▁with ▁dep riv ation ▁after ▁ 3 0 ▁days ▁and ▁ 1 2 0 ▁days . ▁This ▁study ▁suggests ▁that ▁the ▁function ▁of ▁the ▁brain ▁depends ▁on ▁visual ▁input . ▁Michael ▁lost ▁his ▁eyes ight ▁at ▁age ▁ 3 , ▁when ▁his ▁vision ▁was ▁still ▁not ▁fully ▁developed ▁to ▁distinguish ▁shapes , ▁draw ings ▁or ▁images ▁clearly . ▁It ▁would ▁be ▁difficult ▁for ▁him ▁to ▁be