I get asked about the Head Knight helmet quite a bit. Before this helmet and lens system I would ski without goggles because contact lenses had become to irritating, and I prefer to have corrective lenses most of the time. This system is great for everybody, but particularly useful for people who wear glasses and want a nice and affordable option.
Having purchased this helmet in the 15/16′ season, I have purchased a new helmet for the 18/19′ season. The new helmet is blue and comes with an extra lens for even more versatility. I could easily have gotten another year out of the helmet, but my father wanted it for snow blowing since it is warm and provides a nice face shield.
One issue I did have with this helmet system was snow entering the top of the lens on powder days. This never happened in the east since the snow flakes are a bit larger, but in Colorado it was an issue on a few days per year. Keep in mind that I skied over 300 days with this helmet, so a few days was not a deal breaker.
If you are in the market for a new helmet or goggles, definitely take this system into consideration. It functions well, and looks pretty good when the lens is down!