Like a modernized version of classic glacier glasses, the Tsuga comes equipped with removable side covers. When on, they block peripheral light without obstructing your vision. They also limit airflow for high-speed or windy situations—the very situations that will make you grateful for the Tsuga’s hydrophilic, anti-slip nose pads & temple tips. Take the side shields off and the Tsuga transforms into a fashionable, casual model.