Debian uses Perl as a dependency for many of its applications so its not wise to mess with the installed version of Perl.
If you would like to try out your code with a different verion of Perl like 5.10 then you should install perlbrew. It allows you to test your code against multiple versions of perl by having multiple perl installations on the same system in a easy to manage way.
You can install perlbrew from debian repository
sudo apt-get install perlbrew
Once you have installed Perlbrew you can manage your Perl versions easily.
following commands install Perl 5.16.0 and switch your active Perl version to 5.16.0
perlbrew install perl-5.16.0
perlbrew switch perl-5.16.0
Then you can run your scripts using the Perlbrew command
perlbrew exec perl myprogram.pl