I never used to wear them, but often ended up with dust and particles in my eyes - the sun is not such a bother to me, however, my husband has delicate eyes and introduced me to the triple colour interchangeable full glass/goggles available from Halfords - they are excellent and since wearing them I never have trouble with my vision on the bike - I almost feel as if I'm not wearing glasses at all. The only tip I'd give with these is that if you are setting out in the cold mornings, put them on for a few mintues before setting out to adjust to your body temperature, or you will need to stop and demist them !!
Jeanette