And we shouldn't believe this, the whole picture of the world is not just not objective, but very subjective. The eyes can give more complete information about the outside world than the sense of smell, touch, hearing, smell.
Reality ends on the inner shell of the eye. Everything that happens next is the process of "splitting" and reproducing this reality. The fact that we reproduce reality more or less adequately is evidenced by the fact that we are alive and even developing. But I agree, there is no certainty that visual information at any given moment of time corresponds to objective reality, because the "world" with all its "predictable and readable" images has already been recorded in the brain, and now, in order to "see" something completely you don't have to see it.
First, they shouldn't. Eyes often give the wrong picture (though this is not a problem of the eye, but of the brain, which incorrectly converts information received from the eyes, but oh well), and in such cases it is better to rely on something else (logic, for example).
If we talk in general and forget about "optical" illusions, then we get something like the following: since the eyes are our main "receiver" of information from the outside world, then not trusting them means deliberately limiting the flow of incoming information, which is nothing good for us, including for our psyche, will not end.
Something like this.