Cabin pressure

[Newark_Anagram]

Could someone tell me what the standard pressurisation is in the cabin, in, for example a 737. I have a friend with an eye problem who has been told she may not be able to fly in two weeks time due to the cabin pressure. I understood that the cabin was not pressurised to ground level pressure, but to something higher, therefore being at a lower pressure than ground level. Is this correct? If so, to what altitude is the cabin pressurised???

Thanks for any help.

[spannersatcx]

Cabins are pressurised to a differential pressure to maintain a certain cabin altitude.

On average the max diff pressure could be around 8 psi, this could give a cabin altitude of say 8000'. (this is a generalisation as every a/c is different, but fairly average).

[Newark_Anagram]

Thanks spannersatcx