How do our sensory organs work automatically without our conscious effort?
Because consciousness evolved much much later than sense organs, and consciously seeing does not make much sense evolutionarily speaking.
We can consciously direct some sense organs, like the eyes, but signals sent sense organs by their very nature have to activated by outside stimuli otherwise they don't work as sense organs. If I could command my taste buds to taste cheese pizza while eating hay or poison it kinda defeats the purpose of having taste buds in the first place.
You really don't tell most of your body to do anything it happens automatically, becasue there is no benefit to doing it consciously, humans have more ability for fine motor control of some muscles becasue they help with things like speech or tool making, but having to learn to consciously control pupil dilation would take much longer and likely result in quite a bit of damage to the eye.
Now our eyes do have to learn how to see (or at least how to focus) and our brain has to learn how to interpret the impulses from our sense organs, but this is not really conscious learning. there is a cool experiment you can to to reteach your brain wrong see the inverted vision experiment but all the learning is without you being aware of it.