I once had this conversation with a friend: He argued that we live in an objective world and that if we put all seven billion people- the current human population- in front of an object (a bottle was in front of us at the time) they would all agree that they are seeing the same thing. I replied that yes, they will agree that it is, for example, a bottle, but everyone will see a different bottle.

Because first of all she/he will see it from a different angle than others. Second, Refraction will be different for everyone. Third, everyone has a different anatomy: our eyes have different structures, they are not the same distance apart, not to mention a possible particularity that someone may have (eg one eye only, short sightedness or long sightedness, astigmatism, etc.), they may also wear glasses that cause an extra refraction etc.)