well if it were possible to simulate the universe perfectly it would point to the "real" universe being a simulation.
Artificial reality wouldn't have to be everywhere perfect to be a convincingly real experience for an average person in an everyday situation. If you see/feel yourself take off your AR equipment and putting it away in the cupboard, you're going to believe you're back in reality, unless something stands out absurdly giving you a reason to judge what has happened and to reassess where you are.
Obvious examples might be the lower quality of the graphics/sound/smells/tactile sensations compared with reality. But what if these were relatively close facsimiles? What would prompt you to say "this isn't reality". How many seconds/minutes would it take to test reality? What would your test be?
Artificial reality may be made more convincing by using the same trick as dreams. Dreams are not perfect, although at the time you believe them to be real, and this is because the judgmental areas of our brains are largely deactivated during sleep, and we are unaware that they are deactivated.
Although that isn't applicable to these sixth sense devices, as we step towards greater AR methods, losing one's sureness about whether or not we've exited the artificial environment, does become increasingly problematic.