Can anybody tell me how to stop the letters and no: rubbing off my remote contro

[mini49]

I need help with my remote control, the letters and numbers keep rubbing off after a few months, you can't see what your doing, can anyone suggest anything please, Thank you.

 

[ssddx]

the numbers are not molded into the keys and are either printed on or stuck on. honestly there is not much you can do except trying to paint nail polish or other coating on top to act as a wear surface.