As seen from the surface of the moon, both the sun and the stars are clearly visible. From a space habitat above the earth's atmosphere, both the sun and the stars are visible at the same time. As from the moon's surface, there is no skylight to overwhelm the starlight. You know you are illuminated by visible light even in the shade, for your friends can easily see you. This is because even though direct sunlight is blocked, visible light is scattered by the atmosphere and you are illuminated by skylight.
Ultraviolet radiation is scattered even more by the atmosphere.
So you can get a sunburn in the shade-by scattering and reflection as well. Such glasses eliminate the distraction provided by the more strongly scattered blue and violet light yet let the pilot see in a frequency range where the eye is sensitive. Light travels faster through the upper atmosphere where the density is less and there are fewer interactions with molecules in the air. The statement is true. An orange sky indicates preferred scattering of low frequencies.