Why Creating views in 11.2.0.1 EE RDBMS and trying to DESC the views reports column sizes which neit

We have 11.2.0.1 on linux 64.
Creating views in 11.2.0.1 EE RDBMS and trying to DESC the views reports column sizes which neither reflect the underlying column size nor the substr column size.

Please check my steps below

select version from v$instance;
drop table alan;
create table alan (c1 varchar2(20), c2 varchar2(40));
create or replace view alan_vw as select distinct substr(c1,1,10) c1, substr(c2,1,20) c2
 from alan;
desc alan
desc alan_vw


VERSION
-----------------
11.2.0.1.0

1 row selected.


Table dropped.


Table created.


View created.

 Name                                                                                              Null?    Type
 ------------------------------------------------------------------------------------------------- -------- ---------------
 C1                                                                                                         VARCHAR2(20)
 C2                                                                                                         VARCHAR2(40)

 Name                                                                                              Null?    Type
 ------------------------------------------------------------------------------------------------- -------- ---------------
 C1                                                                                                         VARCHAR2(40)