Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
This is just a little build I use to play Lux. I never seem to have any problems with this build at all as it gives her the staying power as well as the damage needed to stay in lanes and be a threat. Exhaust is one of my choices for spells as you can use it to either slow down someone running away so you can land your own slow or snare or to perfectly aim that ultimate. Its also great for helping you slow some obnoxious chasers, coupled with Flash to let you disappear into the night. This build is great for soloing mid, thats the reason for taking Lucent Singularity first as you can really annoy the heck out of other mid casters. I'll try to make a more detailed explanation of this as it is my first build ever posted so hopefully you try it out and tell me how it goes.