huh?
this makes no sense.
properly performed laser requires a number of treatments every few months (time depends on area treated) and will be anywhere from 3 - 8 treatments. laser cannot eliminate fine hairs.. hence it is a permanent reduction. it will only be effective on the coarser, darker hairs. finer hairs that keep coming back aren’t being permanently destroyed and there is no point continuing with laser.
you will not need a ‘touch up’ later unless (a) the follicles weren’t destroyed due to ineffective settings (b) you deveop new hair.. on somewhere like the legs this is very, very unlikely to happen.
laser on the face is a bad idea.