Thanks for the reply,
I am actually using FSX Steam Edition at the moment. I agree that it does sound like that is the issue. But I am confused by the idea that my computer, which can usually handle large and more recently released payware scenery, Aerosoft, Taxi2Gate, FlyTampa, etc would have this issue landing at Dublin, a medium sized airport, but I can land at significantly bigger and busier airports such as Aerosoft Heathrow, Taxi2Gate Charles De Gaulle, and FlyTampa Amsterdam and there is no equivalent blurries effect.
That is what suggests to me that it is a problem with the scenery not the system, but I could be wrong. If I switched to Eiresim Dublin this problem would not be apparent but I don't wish to do that. If I reloaded the level of detail radius the problem goes away but it risks crashing FSX and breaks immersion so I don't see that as a viable solution. I have reverted back to a default cfg and the problem persits so I am a little stuck with what to do unfortuately.