Define normal.
I have some difficulty differentiating blues and greens sometimes but I found those shades to be quite distinct even on a low quality screen.
Perhaps your colour differentiation is worse than you think? It could be down to monitor settings though, for example.
There's an Ishihara test here - http://colorvisiontesting.com/ishihara.htm FWIW but I'd imagine you'd need to see an optician to do it correctly.
Define normal.
I have some difficulty differentiating blues and greens sometimes but I found those shades to be quite distinct even on a low quality screen.
Perhaps your colour differentiation is worse than you think? It could be down to monitor settings though, for example.
There's an Ishihara test here - http://colorvisiontesting.com/ishihara.htm FWIW but I'd imagine you'd need to see an optician to do it correctly.