I would avoid using the public group. Try the following instead:
use your_target_database
go
create role db_view_schema authorization [dbo]
grant view definition on schema::[dbo] to [db_view_schema]
go
exec sp_addrolemember @rolename='db_view_schema', membername='security_account'
go
RegardsRudy KomacsarSenior Database Administrator"Ave Caesar! - Morituri te salutamus."