Hi there Valleygirl,
And welcome to forum. That's interesting that you can see the difference in the eyes of the portrait. Some laser copies are hard to notice there. A bit of water usually betrays its lowly origin.
Another way most counterfeits are easily detectable to most collectors is by their odd serial numbers. Typically the prefix is non-existent, and if it is a copy of a current prefix used by BOC, it is more often then not - printed using an incorrect font. Put the note next to a circulated note and you'll see the difference quite quickly.
