As Fairweather says, the CAA require a minimum of one year between laser treatment and issuing a Class one medical certificate.
My understanding is that the reason for this is to allow for any adverse reaction which may occur, their research has concluded that there is no "normal" recovery afterwards i.e. everyone is different in that respect.
In this world of "sue at a drop of hat", you can hardly blame them for wanting to be absolutely sure.
To put it bluntly, if you pay £2 - £3K for the treatment, expect a year off work.