I generally believe in glasses and wear them even in the dark (clear lenses). However, there are conditions when I think they do more harm than good. I cannot find a way to keep them clear in thick fog or constant mist. Also, when there are snowflakes in the air, prepare to be able to see nothing. If you use them in the dark when it's rainy on rural highways, be prepared to be dazzled from starbursts from oncoming lights.

Fortunately, most circumstances that glasses don't work well in tend to wet situations where there is less debris in the air. I use a glasses mounted mirror partly to force myself to wear them. Even with the best lights, you might not notice branches that can drag across your face until it's too late.....