We say an object is there because we can see it or feel it. We know of its existence because of certain properties we perceive they have on the basis of which we say the object exists. We ,with our superior intellect which we pride ourselves so much with, have given certain units that give the object its existence - like length , breadth,shape color etc. But are these units absolute to make them real so that we can depend on them to prove the existence of any object?
Take distance (length, breadth etc.) for example. We say a table is two meters long. But to an ant at one end of the table , it may be not so. It will say the table is one Km long or half a day long. Who is right? Both perhaps.Similar is the case with breadth and all units of distance. A man travelling by air from London to Ny will say it took him nine hrs . But another man travelling the same distance by sea would say it took him several days. Both are right . So the unit of distance which is the basis of existence of an object is not absolute - only relative and hence unreal. Now take the shape of the object which you say is real and existing before your eyes. The shape of the object depends entirely on the nature of your optic lens and attendant optic paraphernalia. If another animal has an optic lens different from man's what is round or square to us may be some other shape to that animal. Or if one has a lens of a different type than the rest of us what he sees and feels will be different from what others see. I mean he may see a round object as some other shape. Color and smell also depend entirely on the property of our respective sense organs. These vary from species to species and even person to person at times. Therefore it is clear from all this that every property or attribute that gave an object physical existence is only relative and not absolute and hence unreal. In short all this goes to show that what we see is/are not really what we think we see. This is quite unsettling. It gives man's cocksuredness a full body blow. Suddenly the real becomes unreal.
Munzly
a vibration field actually... so funny to think that the chair I am now sitting on is full of emptiness... 
Reality! Can't live with it, Can't live without it
I hate to sidetrack your nicely prepared argument, but to compare how any two vastly different creatures perceive an object, one needs to go deeper into the perceptive mechanism than the physical form of their eyes or other sensory appurtenances.
The brain perceives an external object by creating an internal model of it. This is not a conventional three dimensional model as one might expect, but consists of a complex dataset distributed through various areas of the brain. When the mind needs to refer to the external object it recalls the relevant dataset and "appreciates" it in a meaningful way. The conscious mind then tells itself that it is "seeing" the object.
In fact, from recent experimentation, it is understood that when one looks at an object, one doesn't "see" it at all, what happens is that the brain processes the input and creates the dataset, which can then be recalled in exactly the same way as if it was a memory. We are, therefore, all living very slightly in the past. Obviously the mind can usually tell how old or new a dataset is, but this is not always the case, hence the "deja vu" effect and various other weirdness.
So, it is very possible that since many creatures minds evolved from a common ancestor, their actual internal models of objects may be very similar or even identical, despite the different ways the creature has acquired the originating sensory data.