Why do we have two eyes if we only see one image?

What shape are our eyes? What are they made of? How do they work? What’s the point of having two eyes if we only see one image? Why do we blink? What’s the point of tears and why are they salty? We answer your questions about eyes in the first of two episodes with Dr. Sujata Singh, a pediatric ophthalmologist at the University of Vermont Medical Center.