Third Eye controllers – the ones I have seen, anyway – have a wiper that wipes over a resistor coil with very fine resistor wire on it. Like it or not, there will be wear. Eventually the wear is likely to break one of those wires, and then you'll need to have the controller serviced in order to replace that coil.
My suggestion: that resistor coil is mounted via stiff wires at both ends. Perhaps once a year or so, open up your controller and carefully bend those mounts to move the coil either a little closer or a little farther away from the trigger pivot. Make sure the wiper still moves smoothly across its full travel along that resistor coil when you're done. This will cause the wiper to contact a slightly different path on the resistor coil, one that hasn't seen any wear up to now. You can probably see it; you can see the path that the wiper had been using, and with only a few strokes of the trigger you'll be able to see the new path right beside it.
This essentially starts the wear clock over at zero. Presuming you can find three or four positions that all work smoothly, you should be able to squeeze a few more years out of that resistor coil before you'll need to replace it.
