Transitions lenses are photochromic, which means they darken on exposure to UV radiation - clearing in low ambient light conditions but darkening in bright sunlight. In effect this gives you one lens for all light conditions.
But if that's not enough you can also easily change the lens on the Khyber through what Nike call a 'push-and-pull' bracket system; you effectively push and pull the goggles' outriggers to remove one lens out and pop another in, which is all quite easy and can be done in a matter of seconds, although you will need to remove your gloves. It does mean that whatever the light conditions you can be prepared though.
The Khyber ups the comfort factor by offering a flexible polyurethane frame which moulds to your face shape along with the double-layer face foam.
It's designed to fit a medium-large face, and although it doesn't offer the widest field of vision available it will certainly be good enough for most people. The Khyber also comes with a durable water repellent mesh around three-quarters of the frame to enhance airflow and repel exterior moisture, so fogging isn't an issue.
In addition, you get a sturdy carry case and a cloth bag, along with stylish good looks, so although the Khyber is expensive you do get quite a bit for your money.