Banknotes looking too bright or smudged under the UV light

Hi, some banknotes appear to look “weird” under the 365nm UV light:

1. the entire note is unusually bright with no signs of any original UV features

2. certain areas of the note look as if splashed with some liquid

3. there are multiple scattered small dots throughout the note's design

Do the above always mean that a banknote has been washed (and pressed)?

By how much washing reduces the grade/value of a banknote?

Thanks in advance!

Exposure to UV light will often show damage caused by moisture, including cleaning.

Here is an image of an Irish Series B £10 note under UV.

The strip down the centre is the normal UV active area of the note. The blue splotches at the edges are indicative of moisture damage. This note, otherwise UNC, was damaged when it got wet in an accident.