Many people have difficulty accepting the teaching that our perceptions of objects are in fact internal mental representations, more revealing of our own capabilities, tendencies, and dispositions than of any verifiable external reality. The teaching appears counterintuitive, or perhaps a mere philosophical abstraction, with no bearing on daily life. After all, how can anyone refute the evidence of our senses?
Consider, for example, that human beings cannot hear sounds above or below certain registers, or that we cannot see colors above or below a certain spectrum. The same is true of tastes, odors, and tactile sensations. There are other beings whose perceptual capacities are vastly more acute (or significantly less so) than our own.
The objects revealed by perceptions outside our sensorial range simply do not appear to a human consciousness; for all human intents and purposes, they do not seem to exist. Even this cursory analysis demonstrates that the perception of objects is dependent on the consciousness of the perceiver.
We go about our lives with complete disregard for a plethora of objects that are simply inaccessible to our awareness. However, there are other beings whose experiences are populated by perceptions of these objects, which often constitute the very core of their lives.
It is our particular ‘brand’ of consciousness that dictates the range and scope of our perceptions. And it is those perceptions that constitute the world of our experience, the reality we inhabit.
Great Middle Way 
Does the confusion perhaps arise because the conventional meaning we assign to reality as it is mentally constructed by our senses does in fact have a validity? E.g., I see an octagonal red and white sign, it has squiggles on it which I interpret as letters and writing; this writing has a meaning: “Stop.” I stop my car. If I ignore the sign, I cannot then dispute its ultimate reality with the police officer who has witnessed by inattentive and careless behavior. To understand that objects are actually mental constructions based on our perceptions and that they do not exist in and of themselves — permanent, stable, eternal — is not to deny that they have a provisional purpose in our everyday lives.
The purpose of this teaching, as I understand it, is to help us realize the nature of emptiness. Conditional reality is not ultimate reality; conditions will change and when we invest too much of our trust and belief in its provisional existence we are setting ourselves up for disappointment (suffering of change). But this is not to say that conditional reality does not have a function in our shared conditional existence. Our senses are not useless, only limited.
Sense perception has a valid function. Because we are presently conditioned, we are subject to conditional reality, and must act appropriately. Sense perception has no access, however, to ultimate reality.