Yes, they can see through it, but the ThunderCap does filter the dogs vision in order to reduce the visual stimulation that the pet experiences which helps them in stressful situations.
Useful Information
Sizing:
XSmall – Snout Circumference – 3″-6″, Eyes to Collar – 2.5″-5″
Small – Snout Circumference – 5″-8″, Eyes to Collar – 5″-9″
Medium – Snout Circumference – 7″-10″, Eyes to Collar – 7″-12″
Large – Snout Circumference – 9″-12″, Eyes to Collar – 9″-16″