Yes, there is a reason why cycling glasses tend to be large. Think of cycling glasses less of a fashion accessory and more of a purpose-built tool.
- Peripheral vision: if you want to check your rear for traffic or scan a trail, you need peripheral vision. With narrow glasses, you will have a harder time and need to move your head more.
- Drafts and dry eyes: On road bikes especially, big gaps between your face and the glasses means that you will likely have a draft going in between your face and your glasses. Your eyes will dry out. Not pleasant.
- Insects and debris: While rare, if the gap is very large, insects can get caught in the gap, which is very unpleasant. I really dislike it when an insect gets stuck in between my helmet and my head. Debris is more of an issue when you are riding in the wet or offroad. Riding in water and mud, your face might get sprayed.
I would also suggest that you look into getting photochromic lenses that change their tint with brightness. I can wear mine in the complete dark and during the day.