Did you know that you still need to wear eye protection, against sunlight even in winter? It maybe difficult to believe, but the sun can still damage your eyes even in winter (even out in the snow). Therefore it is important that you continue to wear your sunglasses all year round.
If you find that you aren’t getting enough light through your grey tinted sunglass lenses, then you might want to try a brown tinted lens for winter. The brown tint lets more light through and tends to enhance colours so that they work better when their is less light about that the grey tinted ones.
Polarised lenses are wonderful to combat against the glare, that seems to be more of a problem in the winter afternoons. As the angle of the sun is making the light come at a different angle to earlier in the year. I always notice when driving home in the later afternoon/evenings that the cars visor doesn’t seem big enough. The sun just seems to be able to bounce under it, so that sometimes even with my sunglasses (polarised) I still find it difficult.
I worry about the people that don’t have sunglasses on, as it must be nearly blinding for them. The reflected glare of water and snow can actually burn the front of your eyes. Causing a condition known as snow blindness, it is really painful and easily prevented. If it happens to you, then you need to see your local Optometrist/GP and get treatment, cold compresses and loads of lubricants may help in the short term until you can get an appointment.
Much better to prevent it from happening by wearing suitable eye protection.