I was wondering why they are doing this. Luckily they have a leaflet which includes some "Frequently Asked Questions". Here is the one that tackled my question:
Q: What has the Bank if Ireland moved to a Visa Debit card?
A: Visa is an international brand that offers more convenience, greater access to your money, and more protection for the goods you buy.
So the Bank is asking us to believe that the reason they are going to the trouble and expense of replacing existing cards is for the good of their customers.
Pull the other one!
It is bad enough that the Bank is one of the banks (albeit not the worst of them) that has brought this country to its knees. But now they have decided to lie to their customers. And we own the Bank!
Now I don't claim to know why the Bank is doing this. But I certainly don't believe that the only (or even the main) reason is because it is better for customers.