Question

We can see Response area objects because light Response area are altered by the objects. Unless an object is perfectly transparent, a little of the light bounces off by the property of Response area. Most of the light Response area bends by the property of Response area as it passes through a clear object. For example, when you look at a glass, Response area bends the light as it passes through the glass and the background image ends up changed. Your Response area interprets the rays reaching your eye. It determines the shape of the cup by how the background image is distorted.
If the refraction of a clear material can be canceled, the object could be made invisible. A correctly shaped object could be made invisible to the eye. These objects would need Response area sides. The refraction entering the object and the refraction leaving would cancel out.

Responses
-refraction
-parallel
-wave
-transparent
-rays
-brain
-reflection