Accessible Cursors

SELECT oc.user_name, st.sql_text
  FROM v$open_cursor oc,v$sqltext st
 WHERE oc.address    = st.address
      AND oc.hash_value = st.hash_value
 ORDER BY oc.user_name, st.piece
 
For performance reasons, pl/sql cursors are cached for future reuse. So once you use them up they will be added to LRU list of cursor table. Hence you can see them in v$open_cursor.          
Actual Open Cursors
select sum(a.value), b.name
  from v$sesstat a,v$statname b
 where a.statistic# = b.statistic#
   and b.name = ‘opened cursors current’
 group by b.name