Unlike regular glasses, but there is a slight border around the edge of the LCD area which sets them apart. As the FF in the name suggests, they are the full frame version of the glasses, but are also available in a half frame (the Variotronic S, for the same price). They have a nose pad and rubberised sections on the arms, which gives them additional grip and keeps them on your head. It means they are comfortable to wear on longer rides and you don’t get too sweaty on the nose or top of the ears.
You can recalibrate the glasses while riding to make sure they are at the best brightness for the conditions and this is simply done by holding down the button for three seconds. I needed to do this a couple of times, but generally they managed to get the tinting about right for the conditions at the time. They can also be set to on (full tint of 64%) or off (only slight 16% tint), and offer 100% UV protection. This is done through the large and easy to use button on the left hand arm, next to the light sensor.