There is no such thing as a permanent visa. Perhaps the poster means permanent residence / permanent resident, which is issued as a lifetime certificate for lifetime not as a visa.
A visa has an expiry date, some visas can be renewed some can't, in all cases the holder must reapply and go through the consideration process.
Permanent residence (or more correctly called A Certificate of Residence*) is issued for lifetime, it has no expiry date, it never needs renewal and never needs review but it does automatically cancel on the death of the holder.
(* not to be confused with the simple letter 'Certificate of Residence' which is a 'proof' of address letter as needed to renew a drivers license etc. This is NOT a permanent residence indicator / proof.)