I thought I was smart...

BEFORE

function vis(el, on) { if (el) { on ? remClass(el, 'nosee') : addClass(el, 'nosee') } }

AFTER

function vis(el, on) { if (el) { window[on ? 'remClass' : 'addClass'](el, 'nosee') } }

...sadly we have to add window when using the square brackets so it's not much shorter. Oh well.