Clearance for illuminated mirror above bathroom basin?

[fiveminutejob]

We are having one of those 18watt illuminated mirrors (Zone 2 rated it says) fitted over a bathroom handbasin. It has a pull cord about 5/6cm at centre of bottom edge. What is regulation safety clearance between bottom of mirror/lightbox and top of basin, please?

(Mrs fiveminutejob says she needs it low enough so that she doesn't need to balance on three library books to see herself properly).

Thanks in advance...

 

[fiveminutejob]

I should have added that the installation instruction leaflet for the mirror does not mention clearance at all.

 

[Taylortwocities]

Zones in a bathroom relate to distances from the bath or shower, basins dont come into play..

Zone 2 is generally the area immediately above the basin up to a radius of 600mm from centre of the basin.

The means that you can mount your mirror as low as the bathroom dwarf needs it.